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Showing 715 types of WEEDS

Alexandergrass

Latin Name: Urochloa Plantaginea

Native to tropical America and found throughout South and Central America, in the United States from Florida north along the Atlantic coast states to Pennsylvania, as well as in Hawaii.

Alfalfa

Latin Name: Medicago Sativa

Native to Eurasia, but introduced as a forage crop, and now grown extensively as animal feed. Often escapes or is seeded along roadsides by transport, becoming established in waste places and roadsides.

Alkali Heliotrope

Latin Name: Heliotropium Curassavicum

Native to the United States

Alkali Weed

Latin Name: Cressa Truxillensis

Native to the western United States, and found from Texas to the Pacific Coast states, and south into Mexico.

Alkalki Sida

Latin Name: Sida Hederacea

Native to the United States and widespread in the west.

Allegheny Monkeyflower

Latin Name: Mimulus Ringens

Native to eastern North America, and present throughout the eastern half of the continent to the Rocky Mountains, as well as in California, Oregon, and Idaho.

Alsike

Latin Name: Trifolium Hybridum

Native to Europe, but now widespread in the United States along the Pacific and Atlantic coast states.

Alyce Clover

Latin Name: Alysicarpus Vaginalis

Native to the Old World tropics, but introduced to the U.S. and now found throughout the southeastern states north to Virginia, as well as in Hawaii and the West Indies.

American Black Nightshade

Latin Name: Solanum Spp.

Native to Eurasia – around 1200 species of nightshade occur worldwide. In the United States Eastern Black Nightshade occurs east of the Rocky Mountains, while other species occur in the western U.S.

American Bluehearts

Latin Name: Buchnera Americana

Native to the United States as a wildflower, and found throughout most of the eastern half of the U.S. This is a threatened or protected species of plant in several northeastern states.

American Burnweed

Latin Name: Erechtites Hieraciifolia

Native to North America and found in all states east of the Rocky Mountains, as well as along the Pacific Coast states. It also is found in Hawaii, eastern Canada, the West Indies, and in Mexico through Central America.

American Pondweed

Latin Name: Potamogeton Nodosus

Native to North America, and found throughout the United States including Hawaii, as well as throughout much of Canada.

American Water-plantain

Latin Name: Alisma Subcordatum

A native plant in the United States, and found throughout the eastern half of the country, west to Texas and to California and Oregon.

Anderson's Thistle

Latin Name: Cirsium Andersonii

A native thistle in the Pacific states, occurring in California, Nevada, and Oregon.

Annual Blue-eyed Grass

Latin Name: Sisyrinchium rosulatum

Native to South America but an escape from cultivation that now can be found from California to the southeast states of North Carolina to Florida.

Annual Bluegrass

Latin Name: Poa Annua

Native to Europe, but one of the most widely distributed weed grasses in the United States. It thrives in turf, gardens, crops, roadsides, or any other open area.

Annual Bursage

Latin Name: Franseria Acanthicarpa

Native to western North America, and occurring from Texas north into Canada and all states west of this.

Annual Pricklypoppy

Latin Name: Argemone Polyanthemos

Native to the Rocky Mountain region, and found widely in the western United States, particularly on over-grazed lands. It also occurs on waste areas and along roadsides.

Annual Sedge

Latin Name: Cyperus Compressus

A native of North America, and found throughout most of the eastern United States and as far west as New Mexico, as well as in Hawaii, Mexico, and the West Indies.

Annual Sowthistle

Latin Name: Sonchus Oleraceus

Native to Europe and found commonly throughout North America.

Arizona Popcorn Flower

Latin Name: Plagiobothrys Arizonicus

Native to the western United States, and found in the dry, arid environments from California east to New Mexico, and south into Mexico.

Artichoke Thistle

Latin Name: Cynara Cardunculus

A native of the Mediterranean region this thistle was introduced to the United States as an ornamental and food crop, but its rapid spread and invasive habit have made it a serious rangeland weed in California. It also is found in other countries, such as Australia, as a noxious weed of pastures. The dried flower heads, called “cardoons”, are large and showy, and are prized in arrangements of flowers.

Asiatic Hawksbeard

Latin Name: Youngia Japonica

Native to Southeast Asia, but firmly established as a common weed in the southeast United States and Hawaii. It can be found from Pennsylvania south to Florida and west to Texas.

Asiatic Pennywort

Latin Name: Centella Asiatica

Likely a native of tropical Asia, and now a common weed in Hawaii. It also is found in Oregon and Ohio.

Asparagus

Latin Name: Asparagus Officinalis

A native of Europe, but introduced to the United States as an edible crop. It tends to escape cultivation and can be found throughout the United States and into Latin America, as well as much of southern Canada.

Awned Cyperus

Latin Name: Cyperus Aristatus

May be Eurasian in origin, but now found worldwide, including throughout the United States and southern Canada.

Axilflower

Latin Name: Mecardonia acuminata

Native to the United States, and found in the eastern half from Illinois to Maryland and south to Texas and Florida.

Bag Pod

Latin Name: Glottidium Vesicarium

A native plant in North America, found from Texas throughout the southeast states to Florida and North Carolina.

Bahiagrass

Latin Name: Paspalum Notatum

Native to South America, but now spread throughout all of Latin America, the West Indies, Hawaii, and the southeastern U.S.

Bald Rush

Latin Name: Rhynchospora Nitens

Native to North America, and in the U.S. it is found from Texas to Florida and north along the east coast to New York, as well as in Indiana, Puerto Rico, and Mexico.

Balloon Plant

Latin Name: Asclepias Physocarpa

Native to South Africa, but distributed widely around the world as an ornamental plant. As a milkweed it also serves as a foodplant for milkweed butterflies, such as The Monarch. A common roadside weed in Hawaii.

Balloon Vine

Latin Name: Cardiospermum Halicacabum

Native to tropical areas of North America, and widely distributed as an ornamental vine. It now can be found throughout much of the eastern half of the United States, west to Illinois, Oklahoma, and Texas, as well as in Hawaii and the Caribbean.

Balsam Apple

Latin Name: Momordica Charantia

A native of Asia, this noxious, invasive vine is present in the United States in several eastern states including Florida, west along the Gulf Coast to Texas, and in Hawaii.

Balsampear

Latin Name: Momordica Sp.

Introduced to the southeastern states, and probably native to Asia.

Barnyard Grass

Latin Name: Echinochloa Spp.

Native to Eurasia and Africa, and now occurring throughout North America. This grass will grow in virtually any situation, crop or non-crop, landscape and turf.

Bastard Indigo

Latin Name: Amorpha Fruticosa

Native to North America, and found in nearly every state in the U.S. as well as into Canada and Mexico.

Batchelor's Button

Latin Name: Polygala Sp.

A native plant in Florida.

Bellardia

Latin Name: Bellardia Trixago

Native to the Mediterranean region, but found in northern California and in Texas.

Bermudagrass

Latin Name: Cynodon Dactylon

Native to Africa, but a common weed now around the world. Several hybrids are used as desirable turf.

Biennial Wormwood

Latin Name: Artemisia Biennis

Native to the western United States and found commonly from Colorado to the west coast and north into Canada.

Big Quaking Grass

Latin Name: Briza Mazima

Native to Europe, and introduced to the United States, where it now occurs very sporadically along the West Coast, in Colorado and Illinois, in Georgia and states around New York, as well as in Hawaii.

Big Squirreltail

Latin Name: Elymus Multisetus

Native to the western United States, and found from the Rocky Mountains to the west coast.

Big-head Rush

Latin Name: Juncus Megacephalus

Native to the southeastern United States, where it occurs from Texas to Florida, and north to Maryland.

Bigleaf Mistletoe

Latin Name: Phoradendron Macrophyllum

Native to the western United States, and widely spread from the Pacific Coast eastward into Texas and south into Mexico.

Bird Vetch

Latin Name: Vicia Cracca

Native to Europe, but found throughout the U.S. in the northern states and many southern states, as well as in Canada to Alaska and in Hawaii.

Birdseye Pearlwort

Latin Name: Sagina Procumbens

Native to Eurasia, but now found throughout the United States and southern Canada, particularly in the cooler climates.

Birdsfoot Trefoil

Latin Name: Lotus Corniculatus

Introduced from Europe as a desirable forage plant used in irrigated pastures. Now found throughout the United States and southern Canada as a problem weed in landscape and turf, as well as in cultivated crops.

Birdsrape Mustard

Latin Name: Brassica Rapa

A native of Europe, now widespread in the United States.

Bittersweet Nightshade

Latin Name: Solanum Dolcamara

Native to Eurasia, but introduced to the United States as an ornamental plant. Now found over much of the U.S., particularly common in the east and north central states.

Black Locust

Latin Name: Robinia Pseudoacacia

Native to North America, and in the United States found in virtually all states. A common landscape tree that easily escapes cultivation to become an invasive plant along roadsides and in undisturbed areas.

Black Medic

Latin Name: Medicago Lupulina

Native to eastern Europe and Asia, but now found throughout the United States.

Black Mustard

Latin Name: Brassica Nigra

Introduced from Europe, and now widespread throughout the United States.

Black Nightshade

Latin Name: Solanum Sp.

Black Willow

Latin Name: Salix Nigra

Native to North America, and in the United States found from Texas north to Nebraska and Minnesota, and in all states east of this. It also is found in Canada and south into Mexico.

Blackberry

Latin Name: Rubus Sp.

Native to the western United States, where it is found from southern California into southern Canada.

Blackeyed Susan

Latin Name: Rudbeckia Hirta

A native plant in North America, and found throughout the United States and much of Canada. A number of varieties exist and this is a common ornamental plant in gardens.

Blackgrass

Latin Name: Alopecurus Myosuroides

Native to Eurasia where it can be a severe weed problem. Now widespread throughout the United States, but less of a problem here.

Blackroot

Latin Name: Pterocaulon Virgatum

A native plant, found in the United States from North Carolina south to Florida, and along the Gulf Coast to Texas. It also is found in the West Indies.

Blanket Crabgrass

Latin Name: Digitaria Serotina

Native to North America, and found in the U.S. along the eastern states south throughout Florida, and west to Texas.

Blessed Milk-thistle

Latin Name: Silybum Marianum

Native to the Mediterranean region, and naturalized in the western United States.

Blue Grama

Latin Name: Bouteloua Gracilis

Native to the dry plains of central North America, and found from Alberta, Canada, south in the U.S. to Florida, Texas and Mexico, and west to Idaho and California.

Blue Mistflower

Latin Name: Conoclinium Coelestinum

Native to the eastern United States, and found throughout the eastern half of the U.S. except for the extreme northern states.

Boccones Sandspurry

Latin Name: Spergularia Bocconii

Native to Europe and now found widely along the Pacific Coast states.

Boerhavia

Latin Name: Boerhavia Coccinea

Native to the West Indies, but an introduced and seriously invasive weed in other humid, tropical countries. It is present in the United States from Maryland south to Florida, and from Texas to California. It also is in Hawaii as a very common weed along roadsides and in landscape, vacant lots, and disturbed areas.

Bog Buttons

Latin Name: Lachnocaulon Spp.

Several species of this wildflower are native to the southeastern states of the U.S., and extend across the southern states to the southwest.

Bog Muhly

Latin Name: Muhlenbergia Uniflora

A native grass in North America, occurring in the extreme northeast and north central states and in southeastern Canada.

Bouncing Bet

Latin Name: Saponaria Officinalis

Introduced from Europe as a garden plant, and now found throughout the United States and southern Canada, often as an escape along roadsides or in disturbed lots.

Box Elder

Latin Name: Acer Negundo

Native to North America, and found from coast to coast.

Brachiaria

Latin Name: Brachiaria Mutica

Native to Africa or possibly South America as well, but found throughout the world due to its introduction as a forage grass. It is considered a principle to serious weed pest in crops in many countries of the world.

Bracken Fern

Latin Name: Pteridium Aquilinum

Native to North America, and found throughout much of the continent, from Alaska to the east and west coasts.

Bracted Saltbush

Latin Name: Atriplex Seranana

A native plant in California and Nevada, especially in saline soils.

Brazil Pusley

Latin Name: Richardia Brasiliensis

Native to South America, and now found from Texas along the Gulf Coast and north to Virginia, as well as in Hawaii and Asia.

Brazilian Pepper

Latin Name: Schinus Terebinthifolius

Introduced to the United States from South America as a garden ornamental and source of spice, and now found from Florida west to Texas, possibly common and invasive in some areas. It now can be found in disturbed areas and waste sites, older fields, and even in native areas where it competes with native plants.

Bristly Foxtail

Latin Name: Setaria Verticillata

Native to Europe, Asia, and Africa, introduced to the United States from Europe.

Bristly Hawksbeard

Latin Name: Crepis Setosa

Native to the Mediterranean region and introduced from Europe. Now an occasional weed in the western United States, sometimes common in turf or waste areas.

Bristly Mallow

Latin Name: Modiola Caroliniana

Native to tropical Americas, and widespread in California.

Bristly Oxtongue

Latin Name: Picris Echioides

Introduced from the Mediterranean region, and now a widespread problem weed in northern California, where it can be found in turf, landscape, roadsides and vacant lots.

Bristly Sedge

Latin Name: Carex Comosa

A native sedge found throughout the United States and southern Canada, with the exception of the more arid areas of the southwest U.S.

Brittlestem Hempnettle

Latin Name: Galeopsis Tetrahit

Native to Europe, but introduced as an ornamental plant to the United States, where it is now found throughout the northern half of the country as well as in Louisiana.

Broadleaf Dock

Latin Name: Rumex Obtusifolius

Native to Europe and Asia. Now widespread in the United States.

Broadleaf Enchanter's Nightshade

Latin Name: Circaea Lutetiana

Native to North America, and occurring from Maine south to Georgia, and west in all states to the Rocky Mountains.

Broadleaf Filaree

Latin Name: Erodium botrys

Introduced to the United States from the Mediterranean

Broadleaf Pink Purslane

Latin Name: Portulaca Amilis

Native to South America, and found in the United States from North Carolina to all of Florida.

Broadleaf Plantain

Latin Name: Plantago Major

Native to Europe, but naturalized and now found commonly throughout the United States and southern Canada.

Broom Groundsel

Latin Name: Senecio Spartioides

Native to the western United States.

Broom Sedge

Latin Name: Carex Scoparia

Native to North America, and found throughout the United States and Canada.

Broom Snakeweed

Latin Name: Gutierrezia Sarothrae

Native to western North America, and found in every state from Minnesota and Texas west to the Pacific coast, with isolated populations in a few eastern seaboard states.

Broomrape

Latin Name: Orobanchaceae

Broomsedge

Latin Name: Andropogon Virginicus

Native to North America, and found throughout the United States and down into Central America.

Brown Fox Sedge

Latin Name: Carex Vulpinoidea

Native to North America, and found in nearly every state from coast to coast as well as throughout southern Canada.

Buckhorn Plantain

Latin Name: Plantago Lanceolata

Introduced from Europe, and now found throughout the United States and Canada.

Buffalo Gourd

Latin Name: Cucurbita Foetidissima

Native to the United States and distributed widely from Virginia to California, with little occurrence in extreme northern states or most of the southeast.

Buffalobur

Latin Name: Solanum Rostratum

Native to the Great Plains area of the United States, and now occurring commonly in the Midwest to the west coast.

Buffelgrass

Latin Name: Pennisetum Ciliare

An introduced weed that now can be found in the United States from California to Florida and in Hawaii, as well as sporadically in the Northeast and Midwest.

Bulbous Bittercress

Latin Name: Cardamine Bulbosa

Native to North America, and found in nearly every state east of the Rocky Mountains.

Bulbous Bluegrass

Latin Name: Poa Bulbosa

Introduced from Europe, and now found widely in the western United States.

Bull Thistle

Latin Name: Cirsium Vulgare

Native to Europe and Asia, but now widespread throughout the United States and southern Canada.

Bulltongue Arrowhead

Latin Name: Sagittaria Lancifolia

Native to the southeast United States, where it occurs from Oklahoma and Texas east to Florida, and north to Maryland.

Bunchberry Dogwood

Latin Name: Cornus Canadensis

Native to North America, and found throughout the northern states, throughout Canada and into Alaska.

Burclover

Latin Name: Medicago Polymorpha

Native to Eurasia, and now widespread in the western United States.

Burgundy Stem Taro

Latin Name: Colocasia Esculenta

Native to tropical Asia and the Pacific Islands, this plant is widely sold as an ornamental aquatic plant, and has escaped to become a noxious problem in drainage ditches and other waterways. It may be found throughout the warmer states of the U.S.

Burhead

Latin Name: Echinodorus Berteroi

Native to North America, and widely distributed from Ohio and Texas to the west coast.

Burning Nettle

Latin Name: Urtica Urens

Naturalized from Europe, now common in the west coast states.

Bush Bean

Latin Name: Macroptilium Sp.

A native plant in the United States, and found in the extreme southeast states.

Bush Monkeyflower

Latin Name: Mimulus Aurantiacus

Native to the western United States.

Bushy Aster

Latin Name: Aster Dumosus

Native to North America, and found throughout the entire eastern half of the United States, west to Texas.

Bushy Bluestem

Latin Name: Andropogon Glomeratus

Native to North America along the east coast, and now naturalized in California and Hawaii, as well as Japan and Australia and in the West Indies, Central America and into northern South America.

Bushy Buttonweed

Latin Name: Spermacoce Assurgens

Found in warm, humid climates of most continents, as well as Hawaii, the West Indies, and from Florida to Louisiana. Considered a native in the U.S., but also found throughout Latin America and in Asia.

Buttercup Oxalis

Latin Name: Oxalis Pes-caprae

Native to South Africa, and introduced to the United States as a garden plant, from which it has escaped cultivation to become a common weed pest in both landscape and agriculture. Found throughout the United States and into the West Indies.

California Arrowhead

Latin Name: Sagittaria Montevidensis

Native to South America, but a variety has become naturalized in the United States, and is now found from the Mississippi River and its surrounding states to the west coast.

California Brome

Latin Name: Bromus Carinatus

Native to the western United States, where it is found along the Pacific Coast states from Washington to California.

California Buckwheat

Latin Name: Eriogonum Fasciculatum

Native to the western United States.

California Loosestrife

Latin Name: Lythrum Californicum

Native to the western United States, where it occurs along the southern half from California east to Texas and Kansas.

California Milkweed

Latin Name: Asclepias Californica

Native to California, and currently found only in that state.

California Mugwort

Latin Name: Artemisia Douglasiana

Native to the western United States, and found from southern California to Washington and east to Idaho and Nevada.

California Poppy

Latin Name: Eschscholzia Californica

Native to the western United States, and occurring in many varieties throughout Washington south through southern California.

California Wild Rose

Latin Name: Rosa Californica

Native to the western United States, and just one of several dozen species of wild roses in North America.

Camphorweed

Latin Name: Heterotheca Subaxillaris

Native to North America, and found widely from the east coast along the southern 2/3 of the United States to California, and south into Mexico.

Canada Goldenrod

Latin Name: Solidago Canadensis

Native to North America, and found throughout the U.S., Canada, and north to Alaska. It has been introduced to Hawaii.

Canada Thistle

Latin Name: Cirsium Arvense

Native to southeastern Eurasia, but introduced to Canada in contaminated crop seeds in the 18th century, and now found throughout the northern half of the United States and southern Canada.

Carolina Geranium

Latin Name: Geranium carolinianum

Native to the United States, and widely distributed in the United States.

Carolina Pricklypoppy

Latin Name: Argemone Albiflora

Native to the southeast states of the United States, and now occurring throughout most of the eastern half of the U.S. and into Mexico.

Carpetgrass

Latin Name: Axonopus Affinis

Found throughout the world in mild climates, and in the U.S. in the eastern half of the country.

Carpetweed

Latin Name: Mollugo Verticillata

Native to tropical America, now distributed widely in the U.S.

Castor Bean

Latin Name: Ricinus Communis

Native to Asia and Africa, and now a widespread weed in southern California. Castor bean plants are cultivated for their oil (castor oil) and were imported for this use, but have escaped cultivation to become a problem along roadsides, ditch banks, and waste areas.

Catchweed Bedstraw

Latin Name: Galium Aparine

Native to North America and widespread across the continent.

Chamberbitter

Latin Name: Phyllanthus Urinaria

Native to Asia and introduced to the United States, where it now occurs from Texas to Florida and north into Virginia, as well as in Illinois and the West Indies and throughout Latin America.

Cheat

Latin Name: Bromus Secalinus

Introduced from Europe, and now common throughout the United States.

Chicken Weed

Latin Name: Pectis Prostrata

A native weed, found in the United States in Florida and Texas to Arizona, as well as in Mexico and Puerto Rico.

Chicory

Latin Name: Chichorium Intybus

Native to Europe, but now found throughout the United States, and especially abundant in the northern and western states where it is a common roadside weed.

Chinese Violet

Latin Name: Asystasia Gangetica

A native of Asia, now present in Florida, Hawaii, and the West Indies.

Clammy Groundcherry

Latin Name: Physalis Heterophylla

Native to North America, and found in almost every state except California, Oregon, and Nevada.

Clasping Heliotrope

Latin Name: Heliotropium Amplexicaule

Native to South America, but introduced as an ornamental plant to many parts of the world. It is now present in the United States along the eastern seaboard south to Florida, west along the Gulf States to Texas, and in California and Hawaii.

Climbing Hempvine

Latin Name: Mikania Scandens

A native plant in North America, found in the United States throughout most of the eastern half of the country, and south into Mexico. It has become a serious pest problem on many Pacific Islands due to its rapid growth and smothering habit. It is listed in Hawaii as a Noxious Weed. It is often used as a cover crop, livestock feed, or ornamental plant, encouraging its spread to new regions.

Cluster Dock

Latin Name: Rumex Conglomerates

Introduced from Europe, and now found in the United States from Pennsylvania south to Georgia, west to Texas and California and north to Washington. It also has be introduced to Hawaii, and in Australia it is a listed noxious weed.

Clustered Clover

Latin Name: Trifolium Glomeratum

Native to Europe, but introduced to North America where it now is found uncommonly in the southeast states as well as California, Oregon, and Hawaii.

Clustered Spikerush

Latin Name: Eleocharis Geniculata

Native to eastern North America. It is found in most southern states from California to Florida and north into New England, as well as in the Great Lakes states. It also is in Hawaii, the West Indies, and Mexico.

Coast Fiddleneck

Latin Name: Amsinckia Intermedia

Coast fiddleneck is native to Oregon and California.

Coast Tarweed

Latin Name: Madia Sativa

Introduced from South America, and now distributed along the west coast from Washington to California.

Coat Buttons

Latin Name: Tridax Procumbens

Native to Latin America, but introduced to and common in Florida, as well as Hawaii and the West Indies. It also has found its way to the tropical regions of most other continents and Pacific Islands.

Coffee Senna

Latin Name: Senna Occidentalis

Native to Latin America, but introduced to the United States. It is present throughout the southeastern states from Texas north to Iowa, east to Virginia and south to Florida. It is also present in Hawaii.

Common Blue Violet

Latin Name: Viola papilionacea

A native plant found in every state east of the Rocky Mountains, and in eastern Canada.

Common Boneset

Latin Name: Eupatorium Perfoliatum

Native to North America, and found throughout the eastern half of the continent.

Common Brass Buttons

Latin Name: Cotula Coronopifolia

Native to South Africa but introduced as an ornamental plant to North America, where it now occurs from northern Mexico and Arizona north to Alaska.

Common Burdock

Latin Name: Arctium Minus

Native to Europe, but found throughout the United States and Canada, and listed as a “Noxious Weed” in several states.

Common Buttonbush

Latin Name: Cephalanthus Occidentalis

Native to North America, and found throughout the eastern half of the country as well as in Arizona and California.

Common Catsear

Latin Name: Hypochaeris Radicata

A native of Europe, this weed is now found throughout much of the U.S. and southern Canada.

Common Cattail

Latin Name: Typha Latifolia

Native to Europe – now widespread in the U.S.

Common Chickweed

Latin Name: Stellaria Media

Introduced from Europe, and now widely distributed throughout the United States and Canada.

Common Cinquefoil

Latin Name: Potentilla Canadensis

A native plant found throughout the eastern third of the United States, and west to Wisconsin, Arkansas, and Texas.

Common Cocklebur

Latin Name: Xanthium Strumarium

Native to North America and found throughout the United States, as well as many other temperate areas of the world. It is particularly common in the southern states and into Mexico.

Common Cowparsnip

Latin Name: Heracleum Maximum

Native to North America, and found throughout the United States with the exception of most southeastern states from Texas to Florida. Also found throughout Canada north to Alaska.

Common Duckweed

Latin Name: Lemna Sp.

Many species in several different genera – most are native to the U.S., while some species are introduced.

Common Elodea

Latin Name: Elodea canadensis

Several species of this plant are present in the United States, and most are native to North America.

Common Evening Primrose

Latin Name: Oenothera Biennis

A native plant found throughout the United States and southern Canada, with the exception of the Rocky Mountain states. Commonly sold as an ornamental garden plant.

Common Fennel

Latin Name: Foeniculum Vulgare

Native to Europe, and introduced to California, where it now is extremely common as a roadside weed throughout central to southern California.

Common Fumitory

Latin Name: Fumaria Officinalis

Native to Eurasia, but introduced to North America and now found throughout the United States and southern Canada.

Common Greeneyes

Latin Name: Berlandiera Subacaulis

Native to Florida, and found only in that state.

Common Groundsel

Latin Name: Senecio Vulgaris

Introduced from Europe, and now widespread in the northern United States and Canada, and as far south as Texas and throughout the western states. An extremely common winter and spring weed.

Common Lambsquarters

Latin Name: Chenopodium Album

Native to Europe, and now an extremely common weed throughout the United States.

Common Large Monkeyflower

Latin Name: Mimulus Guttatus

Native to the western United States, and found from Alaska to Mexico and from the Rocky Mountains to the west coast, in many locations below 10,000 altitude.

Common Lespedeza

Latin Name: Kummerowia Striata

Native to Asia, but found throughout much of the eastern half of the United States.

Common Madia

Latin Name: Madia Elegans

Native to the western United States and found from Oregon south through much of California.

Common Mallow

Latin Name: Malva Neglecta

Native to Europe - widespread in United States.

Common Milkweed

Latin Name: Asclepias Syriaca

A native of North America, and found throughout the entire eastern United States and Canada, east of the Rocky Mountains. It also is found in Montana and Oregon, possibly as an escape from cultivation. Commonly used as a garden plant due to its showy appearance and attraction to butterflies.

Common Mullein

Latin Name: Verbascum Thapsus

Native to Asia but introduced to the United States from Europe. Common throughout temperate parts of North America, infesting almost any situation in landscape, crops, or non-landscaped soils.

Common Pokeweed

Latin Name: Phytolacca Americana

Native to the eastern United States, and common in the east, southeast, and southern states, but sporadically occurs to California as well, where it is widely distributed. It is grown as a garden ornamental, but escapes to become an invasive plant in orchards and vineyards, as well as wooded areas.

Common Purslane

Latin Name: Portulaca Oleracea

Naturalized from Europe, and now a common problem weed throughout the world.

Common Ragweed

Latin Name: Ambrosia artemisiifolia

Native to the eastern United States, and still most common there, but found throughout North America.

Common Reed

Latin Name: Phragmites Australis

Native to the South America, but introduced deliberately to the western states as an ornamental plant. Also used for windbreaks, roofing, mats, screens, and even in adobe used for building adobe structures. As an escaped non-native weed it grows readily along the banks of waterways and ponds, interfering with water flow and helping to create stagnant areas.

Common Rye

Latin Name: Secale Cereale

A native of Asia this grass was introduced as a forage plant in the United States. It is now found throughout North America to Alaska, and south into Latin America.

Common Sagewort

Latin Name: Artemisia Campestris

Native to the west coast of the United States from Oregon south to central California.

Common Salsify

Latin Name: Tragopogon Porrifolius

Native to Europe, but introduced to North America as an ornamental plant. It now can be found throughout the entire United States except for a few southeast states and extreme northern states. It is also introduced to Hawaii and is in Canada and south into Mexico.

Common Spiderwort

Latin Name: Tradescantia Ohiensis

Native to North America, and found in all states east of the Mississippi River as well as from Nebraska south to Texas and in eastern Canada.

Common St. Johnswort

Latin Name: Hypericum Perforatum

Native to Europe and now widespread in northern California and into Washington, where it may grow in profusion in pastures, along roadsides, and in waste or abandoned areas. The foliage is poisonous to livestock, especially those with light colored hair and skin, and will cause them to exhibit skin irritation when exposed to sunlight. A leaf beetle (family Chrysomelidae – Chrysolina quadrigemina, the “Klamath Weed Beetle”) has been used successfully to control the spread of this weed.

Common Sunflower

Latin Name: Helianthus Annuus

A native of North America and common throughout the United States.

Common Tansy

Latin Name: Tanacetum Vulgare

Native to Europe, but introduced to the United States as an ornamental plant as well as for its uses as a medicinal herb. It is found throughout much of North America and occurs along roadsides, in empty lots, stream or ditch banks and pastures.

Common Teasel

Latin Name: Dipsacus Fullonum

A native of Europe, and now found throughout much of the United States with the exception of the northern Great Plains. Most common in the northeast and Pacific Coast states.

Common Toad Rush

Latin Name: Juncus Bufonius

Native to North America, where it is found from Alaska to the Gulf States, as well as in many other temperate regions of the world.

Common Velvetgrass

Latin Name: Holcus Lanatus

Native to Europe and now widespread throughout the United States. Less common in the far northern states. It was introduced as a forage grass, but easily escapes cultivated areas.

Common Venus' Looking-glass

Latin Name: Triodanis Perfoliata

Possibly native to South America, but now occurring throughout North America except for the Rocky Mountains, and south through Central America to South America.

Common Vetch

Latin Name: Vicia Sativa

One of many species of vetch introduced from Europe as an ornamental or forage plant. These have escaped to become common roadside and pasture weeds.

Common Water-plantain

Latin Name: Alisma Plantago-aquatica

Native to North America and found from the Atlantic to the Pacific coasts in temperate climates.

Common Yarrow

Latin Name: Achillea Millefolium

Native to Eurasia, but naturalized in the United States and common and widespread throughout North America.

Cone Catchfly

Latin Name: Silene Conoidea

Introduced from Eurasia as an ornamental plant, and now found occasionally along the West Coast in fields, roadsides, and other disturbed habitats.

Contorted Primrose

Latin Name: Oenothera Sp.

This is one of around 200 species of Oenothera in North and South America, and most are native to the Western Hemisphere.

Coontail

Latin Name: Ceratophyllum demersum

Coontail

Latin Name: Ceratophyllum Demersum

Corn Flower

Latin Name: Centaurea Cyanus

Native to the Mediterranean, but introduced around the world as a garden plant and now present worldwide. It is present throughout the U.S. and in Hawaii.

Corn Spurry

Latin Name: Spergula Arvensis

Introduced from Europe, and naturalized throughout the western United States, somewhat in the eastern part of the country.

Cottonwood

Latin Name: Populus deltoides

Native to eastern North America, but widely used as a landscape tree or windbreak, and escaped from cultivation to invade riverbanks and creek banks.

Coyote Bush

Latin Name: Baccharis Pilularis

Native to the western United States, and common in California and Oregon, present in New Mexico.

Coyote Thistle

Latin Name: Eryngium Spp.

Native to the western United States. There are several dozen species of native plants in this genus, many of which are rare and some of which are classified as Protected or Threatened species.

Creeping Beggarweed

Latin Name: Desmodium Canum

Possibly native to Latin America, and now found from Florida to Texas along the Gulf States, in the West Indies and throughout Latin America, as well as in Tropical Africa and Hawaii.

Creeping Bellflower

Latin Name: Campanula Rapunculoides

Native to Europe, but introduced to North America as a garden ornamental, and now found throughout most of the United States and southern Canada, with the exception of the southeastern and extreme southwestern states.

Creeping Buttercup

Latin Name: Ranunculus Repens

Introduced from Europe, and now widely spread across the United States.

Creeping Indigo

Latin Name: Indigofera Spicata

Native to Africa, and now found in a number of Asian countries as well as in Florida and Hawaii in the United States.

Creeping Lespedeza

Latin Name: Lespedeza Repens

Native to North America, and found throughout the eastern United States from Texas north to Wisconsin, and east along the entire east coast.

Creeping Spikerush

Latin Name: Eleocharais Palustris

A native plant found throughout North America, with the exception of Florida and Georgia, to as far north as Alaska and south into Mexico.

Creeping Spurge

Latin Name: Chamaesyce Serpens

Creeping Water Primrose

Latin Name: Ludwigia peploides

Native to South America – one of over 30 species of Ludwigia in the United States.

Creeping Woodsorrel

Latin Name: Oxalis Corniculata

Native to Europe, but widespread throughout the United States, and a severe problem in turf and landscape, nurseries and greenhouses, as well as some cultivated crops.

Crimson Clover

Latin Name: Trifolium Incarnatum

A native of Europe, but introduced as an ornamental plant to many other areas, and now widely spread throughout the United States in the eastern half of the country and along the west coast, as well as in Hawaii.

Crimson Fountaingrass

Latin Name: Pennisetum Setaceum

Native to Africa, but introduced as an ornamental grass to California. As an escape it grows rapidly along roadsides, but rarely causes problems in crops.

Crockeria

Latin Name: Crockeria Chrysantha

Native to California, and found throughout the Central Valley in low-lying areas.

Crowfootgrass

Latin Name: Dactyloctenium Aegyptium

Introduced from the Old World Tropics of Asia or Africa, and now found throughout much of the U.S., particularly in the southern states, and south throughout Latin America, in Europe, Australia, and Hawaii.

Cuban Purple Woodsorrel

Latin Name: Oxalis Latifolia

Native to the West Indies, and present sporadically in the United States in Florida, California, and New Mexico.

Cupid's Shaving Brush

Latin Name: Emilia Fosbergii

Native to the Old World tropics, but now found throughout the tropical regions of the world. In the United States it can be found commonly in Florida, Hawaii, Texas and Louisiana. It also is found through Mexico into South America and in the West Indies.

Curly Dock

Latin Name: Rumex Crispus

Native to Europe and Asia. Now widespread in the United States.

Curlycup Gumweed

Latin Name: Grindelia Squarrosa

Native to the Great Plains of the United States, and commonly found across the western U.S.

Cutleaf Evening Primrose

Latin Name: Oenothera Laciniata

Native to the southeast United States, and now found throughout the U.S. and south throughout Latin America and in the West Indies.

Cutleaf Geranium

Latin Name: Geranium dissectum

Cutleaf Nightshade

Latin Name: Solanum Triflorum

Native to the Midwestern United States, and now widely distributed in the western states.

Cylindric Sedge

Latin Name: Cyperus Retrorsus

A native plant in southeastern North America, now found from New York to Florida, and west to Texas and Oklahoma.

Cypress

Latin Name: Cupressaceae

Cypress Spurge

Latin Name: Euphorbia Cyparissias

Native to Europe, but introduced to North America as a garden plant, and now found throughout most of the United States and Canada, with the exception of the south-central states in the U.S. It is declared a noxious weed in most of southern Canada.

Dallisgrass

Latin Name: Paspalum Dilatatum

Native to South America, now common throughout the southwest United States.

Dalmatian Toadflax

Latin Name: Linaria Genistifolia Dalmatica

Introduced from Europe, possibly as a garden ornamental, and now found as a serious weed problem in the United States throughout the northern states and in the west from Oklahoma to California.

Dandelion

Latin Name: Taraxacum Officinale

Introduced from Europe and now widespread and extremely common across North America.

Deergrass

Latin Name: Muhlenbergia Rigens

Native to the west coast of the United States. Commonly used in ornamental settings due to its size and symmetry.

Desert Marigold

Latin Name: Baileya multiradiata

Native to the southwest states in the U.S. and in northern Mexico. Considered a desirable wildflower, although it may be found invading landscaped areas or growing in large plants along roadsides.

Desert Rock Purslane

Latin Name: Calandrinia ciliata

Native to western North America, and found along the Pacific Coast into Arizona, and south into northern Mexico.

Desert Trumpet

Latin Name: Eriogonum Inflatum

A native plant found in the southwest states, from California east to Colorado and New Mexico.

Desert Willow

Latin Name: Chilopsis Linearis

Native to the southwest states of the United States and into Mexico. It is found from Texas north to Kansas and west to California in the more arid regions.

Devil's Beggarticks

Latin Name: Bidens Frondosa

Introduced from Europe and now found throughout the United States and southern Canada.

Devil's Claw

Latin Name: Proboscidea Louisianica

Native to the southern United States and northern Mexico, but now introduced to and present in almost all states of the U.S.

Diatoms

Latin Name: Diatomaceae

Dichondra

Latin Name: Dichondra Spp.

Several varieties that are native to California.

Diffuse Lovegrass

Latin Name: Eragrostis Diffusa

Native to the western United States.

Dodder

Latin Name: Cuscuta spp.

Many species native to the United States. At least 16 species are found in California.

Dogfennel

Latin Name: Eupatorium Capillifolium

A native plant in North America, and found from New Jersey south to Florida, and west to Missouri and Texas. It also can be found in Latin America south to Guatemala and in the West Indies.

Dovefoot Geranium

Latin Name: Geranium molle

A native of Europe, now widespread in North America.

Doveweed

Latin Name: Murdannia Mudiflora

Native to tropical Asia, but introduced to the United States, where it is present from North Carolina to Florida and west to Texas, as well as in Hawaii and the West Indies.

Downy Brome

Latin Name: Bromus Tectorum

Introduced from the Mediterranean in packing materials, and now widely distributed throughout North America.

Ducksalad

Latin Name: Heteranthera limosa

Dwarf Pearlwort

Latin Name: Sagina Apetala

Native to Europe and widely distributed in the western United States.

Early Watergrass

Latin Name: Echinochloa Oryzoides

Introduced from Asia, and found in California and Hawaii as an occasional weed in waste areas and along roadsides.

Eastern Blue-eyed Grass

Latin Name: Sisyrinchium Atlanticum

Native to North America, and found from Texas north to Missouri, and in nearly all states east of the Mississippi River.

Eclipta

Latin Name: Eclipta Prostrata

Native to the eastern United States, but now spread throughout the country, most commonly found in the southern U.S.

Eisen Water Hyssop

Latin Name: Bacopa Eisenii

Native to the United States.

Elm

Latin Name: Ulmaceae

English Catchfly

Latin Name: Silene Gallica

Native to Europe but now widely distributed in the United States.

English Daisy

Latin Name: Bellis Perennis

Introduced from Europe as a garden ornamental, and now escaped to become a common weed in home and recreational turf.

English Violet

Latin Name: Viola odorata

Erect Pennywort

Latin Name: Centella Erecta

Native to the southeastern United States, and found from Texas to Florida to Maryland, as well as in Oregon and Puerto Rico.

Eucalyptus

Latin Name: Eucalyptus Spp.

Native to the Australian Region, but imported centuries before for their value in landscape and for planting where tree cover is desirable in dry climates. Seedlings and sprouts are extremely invasive, and many areas of the western U.S. now have thick stands that eliminate native vegetation.

Everlasting Peavine

Latin Name: Lathyrus Latifolius

Native to Europe and introduced as a garden vine. Commonly escapes to become a roadside nuisance.

Facelis

Latin Name: Facelis Retusa

Native to South America, but introduced to the United States, where it occurs from Virginia south to Florida and west to Texas and Oklahoma.

Fall Panicum

Latin Name: Panicum Dichotomiflorum

Native to central and eastern United States, now spread throughout the western states as well.

False Garlic

Latin Name: Nothoscordum Inodorum

Introduced from South America and now found throughout much of California in the Central Valley and along the south coastal areas.

False Green Kyllinga

Latin Name: Kyllinga Gracillima

Native to the United States and Latin America, and found in the U.S. from Arkansas east to Georgia and north to New York. It also occurs in Hawaii.

False Rhodes Grass

Latin Name: Chloris crinita

Native to North America, where it occurs from Arizona to Texas, and occasionally found as an introduced grass in the area of New York. It also occurs throughout Mexico and into South America.

Fanwort

Latin Name: Cabombaceae

Fanwort

Latin Name: Cabomba Spp.

Two species of fanwort are native to the southeastern United States, and occur throughout the southeast as native plants, and in the Pacific Northwest and the Northeast as exotic invaders.

Fascicled Beaksedge

Latin Name: Rhynchospora Fascicularis

Another native sedge species, found from Texas east to Florida, and north to Virginia.

Feather Fingergrass

Latin Name: Chloris Virgata

Native to tropical America, now widespread in the western United States.

Feathertop

Latin Name: Pennisetum Villosum

Native to Africa, and introduced as an ornamental grass. This is highly drought tolerant, and as an escape from cultivation it can be a problem along roadsides, in ditchbanks, and orchards.

Female Fluvellin

Latin Name: Kickxia Spuria

Native to Europe and now a weed pest in much of California.

Fern, sweet

Latin Name: Comptonia peregrina Coult

Native to eastern North America, and occurring in the United States from Minnesota southeast to Georgia and along the entire east coast except for Florida.

Fetid Passionflower

Latin Name: Passiflora Foetida

Native to tropical New World areas, such as Virgin Islands, Puerto Rico, and the southeast U.S., where it is present in Florida, Texas, Arizona, and even in Maryland, possibly cultivated as an ornamental. It also is found in the Hawaiian Islands.

Field Bindweed

Latin Name: Convolvulus Arvensis

Native to Eurasia but introduced to the United States, where it occurs throughout the continent, and is considered to be one of the most troublesome weeds here and throughout the world.

Field Horsetail

Latin Name: Equisetum arvense

Native to Europe, but now widespread in the United States and Canada.

Field Madder

Latin Name: Sherardia Arvensis

A native of Europe.

Field Pennycress

Latin Name: Thlaspi Arvense

Introduced from Europe and now found throughout the United States. It grows commonly in grain fields and pastures, and the strong odor of the plant causes a bitter flavored milk from livestock that eat it.

Field Sandbur

Latin Name: Cenchrus Incertus

Native to warm regions of the western hemisphere, and currently found along the coastal states from Virginia south through Florida and west to California, as well as throughout Latin America and in Africa and parts of Asia.

Field Scabiosa

Latin Name: Knautia Arvensis

Introduced from Europe as a garden ornamental, but a common escape that is found along roadsides, rights of way, or in other disturbed sites. Now found throughout the northern half of the United States and southern Canada.

Field Violet

Latin Name: Viola arvensis

Native to Europe, but widely used as an ornamental plant, and now found widely throughout the United States and southern Canada, with the exception of the hotter, drier Southwest states.

Filamentous Green Algae

Latin Name: Zygnematales

Filamentous Green Algae

Latin Name: Cladophora Spp.

Filamentous Green Algae

Latin Name: Rhizoclonium Spp.

Fireweed

Latin Name: Epilobium Angustifolium

Native to Eurasia, but now spread commonly throughout North America.

Fivehook Bassia

Latin Name: Bassia Hyssopifolia

Native to Europe and Asia, now widespread in California.

Flat-face Calicoflower

Latin Name: Downingia Pulchella

A native plant in Oregon and California, and found commonly in early spring as a roadside and meadow wildflower.

Flixweed

Latin Name: Descurainia Sophia

A native of Eurasia, and now found in the western United States.

Floating Pennywort

Latin Name: Hydrocotyle Ranunculoides

Native to North America, and found from Washington south into northern Mexico, east through Texas and Oklahoma to the entire East Coast north to New York. It has escaped cultivation and use as an ornamental pond plant to become a noxious weed problem in Britain and Australia.

Florida Betony

Latin Name: Stachys Floridana

Native to Florida, from which it has been introduced to other areas, and now occurs from Virginia to Texas.

Florida Pusley

Latin Name: Richardia Scabra

Considered native to South America, but found commonly in the southeast United States and into the northeast, in Hawaii and Puerto Rico, and throughout Central America.

Four-flower Yellow Loosestrife

Latin Name: Lysimachia Quadriflora

A native of North America that is found throughout much of the eastern half of the continent, except for the extreme southern states where it may be found sporadically. It is a protected species in New York and Tennessee.

Four-leaved Polycarp

Latin Name: Polycarpon Tetraphyllum

Introduced into the United States from Europe, and found in Texas, California, Oregon, the southeast states and in Pennsylvania, as well as in Hawaii.

Fragrant Flatsedge

Latin Name: Cyperus Odoratus

A native plant in North America, and found widely from California to the entire east coast and south into Latin America. It also is found in Hawaii and the West Indies.

Fragrant Waterlily

Latin Name: Nymphaea Odorata

Native to eastern North America, and found throughout the United States and Canada north to Alaska, due in part to its common sale and use for ornamental garden ponds. It is a listed noxious weed in some states due to its rapid growth and ability to cover wide areas of water.

Fringed Black Bindweed

Latin Name: Polygonum Cilinode

A native vine found in the states east of the Mississippi and in Minnesota, but not generally in the extreme southern states.

Fringed Sedge

Latin Name: Carex Crinita

Native to eastern North America, where it occurs throughout the eastern half of the continent and into Oklahoma and Texas.

Fuzzy Rattle-pod

Latin Name: Crotalaria Incana

Native to tropical Latin America and the southern United States, where it is present from Texas east to Florida and South Carolina. It also has been introduced to Hawaii.

Gaillardia

Latin Name: Gaillardia Pulchella

A number of species of Gaillardia are native plants in North America, occurring throughout the Unites States and into southern Canada, south into Mexico. Gaillardia pulchella is an introduced weed species in Hawaii, and is a native plant in the southwest U.S.

Garden Lippia

Latin Name: Phyla nodiflora

Native to South America, but now widely spread throughout the United States as well as Hawaii, all of Latin America and the West Indies, and Japan and India. It is sold as an ornamental groundcover, and escapes easily to non-landscape habitats.

Garden Spurge

Latin Name: Chamaesyce Hirta

Native to the southeastern United States and Latin America, and found in the U.S. from Florida and South Carolina west to Texas, as well as spotty occurrence in Arizona, California, Michigan, and Maryland. It also is common in Hawaii.

Giant Ragweed

Latin Name: Ambrosia Trifida

Native to North America, and found in nearly every state except Alaska and Nevada, into Canada and south into Mexico.

Giant Reed

Latin Name: Arundo Donax

Native to warmer areas of Europe, and introduced to California as an ornamental and wind-break planting, as well as for use as a roofing material, mats or screens. It easily escapes cultivation and has become a major problem in natural settings due to its aggressive and dominating growth. In particular it is noxious in areas along river shores, irrigation or ditchbanks, and drainage canals. It grows in tall, solid thickets that may overwhelm large areas.

Giant Whitetop

Latin Name: Rhynchospora Latifolia

Native to the southeast United States, and occurring from Texas and Oklahoma east to Florida and North Carolina.

Ginseng

Latin Name: Araliaceae

Globe Sedge

Latin Name: Cyperus Croceus

A native plant in eastern North America, occurring from Pennsylvania south throughout Florida, and west to Texas, Oklahoma and Missouri. It also occurs in Latin America and the West Indies as well as eastern Asia.

Golden Bamboo

Latin Name: Phyllostachys Aurea

Native to eastern Asia, but introduced as an ornamental plant. It can be found in landscape or along roadsides in many states with warm climates, including California and Oregon as well as most of the southeast states from Louisiana to Florida and north to Maryland.

Goldenrod

Latin Name: Solidago Spp.

Over 150 species of goldenrod occur in North America, and some will be found in every state including Hawaii, throughout Canada and into Latin America and the West Indies. Many of the species are native plants in North America.

Goosegrass

Latin Name: Eleusine Indica

Introduced from Europe, but now found throughout most of the United States.

Gopher-tail Lovegrass

Latin Name: Eragrostis Ciliaris

Native to Europe, but now found throughout the world, including throughout Latin America and in North America along the east coast states and west to Texas.

Grassy Arrowhead

Latin Name: Sagittaria Graminea

Native to the eastern half of the United States, and present in nearly every state in the eastern half of the country, west to South Dakota and New Mexico, as well as in Washington state. At least 4 varieties of this plant exist.

Gray Globemallow

Latin Name: Sphaeralcea Incana

A native plant in the southwest states, occurring from Arizona to Texas.

Greasewood

Latin Name: Sarcobatus Vermiculatus

Native to North America, and found throughout the western half of the U.S. and into the prairie provinces in Canada.

Great Valley Phacelia

Latin Name: Phacelia Ciliata

Native to California, and present in much of the state, where it can be a problem in alfalfa fields as well as some vegetable crops.

Green Foxtail

Latin Name: Setaria Viridis

Native to Europe, now common throughout much of the United States, especially in cooler climates. A particular problem in alfalfa fields, but also occurring in other row crops, along roadsides, waste areas, and in landscape.

Green Kyllinga

Latin Name: Kyllinga Brevifolia

Native to either the American Tropics or Old World tropical areas, and now found throughout the southwestern United States and in Hawaii. It is becoming a major problem in ornamental plantings, and in turf, where it quickly and aggressively crowds out desirable grasses.

Gregg's Arrowhead

Latin Name: Sagittaria Longiloba

Native to North America, and found from the Midwest to the Pacific Coast and south into Mexico.

Grey Herniaria

Latin Name: Herniaria Hirsuta cinerea

Native to southern Europe, and now found from Arizona through California to Arizona, in Wisconsin and the Northeast.

Ground Cedar

Latin Name: Lycopodium Complanatum

Native to North America, where it is found from Alaska throughout Canada and throughout the northern third of the United States from Oregon to the east coast.

Ground Ivy

Latin Name: Glechoma Hederacea

Native to Eurasia, but introduced to North America as a garden and herbal plant. It now is found throughout North America to Alaska, with the exception of the dry southwestern states of Nevada, Arizona, and New Mexico.

Hairy Abutilon

Latin Name: Abutilon Grandifolium

Native to South America, but introduced to Hawaii

Hairy Beggarticks

Latin Name: Bidens Alba

A native of North America, but now widely spread throughout many parts of the world. In the United States it occurs in Florida and surrounding states, Missouri, Pennsylvania, and Hawaii, and possibly along the west coast. It also occurs throughout Latin America.

Hairy Fleabane

Latin Name: Conyza Bonariensis

Native to the American tropics of South America, and now found widely across the United States. It is common in the western states but also found along the Atlantic Coast.

Hairy Grama

Latin Name: Bouteloua Hirsuta

Native to the dry plains of central North America, and found from Canada south in the U.S. to Florida, Texas and Mexico, and west to Montana and Nevada

Hairy Indigo

Latin Name: Indigofera Hirsuta

An introduced plant that now is found in Florida and surrounding states, as well as in Puerto Rico.

Hairy Nightshade

Latin Name: Solanum Spp.

Native to Eurasia – around 1200 species of nightshade occur worldwide. In the United States Eastern Black Nightshade occurs east of the Rocky Mountains, while other species occur in the western U.S.

Hairy Vetch

Latin Name: Vicia Villosa

One of many species of vetch introduced from Europe as an ornamental or forage plant. These have escaped to become common roadside and pasture weeds.

Hairy Willowweed

Latin Name: Epilobium Hirsutum

Native to the United States, and found throughout most of the country.

Hairy Woodrose

Latin Name: Merremia Aegyptia

Native to tropical Latin America and Florida, and an introduced weed in Hawaii.

Hairystem Gooseberry

Latin Name: Ribes Hirtellum

Native to North America, and found in the northern United States and southern Canada, from Montana to the east coast and south to Illinois and West Virginia.

Harding Grass

Latin Name: Phalaris Tuberosa

Native to Eurasia, but introduced to the United States as a forage grass and for range improvement. It has spread widely, and now can be found in many states across the U.S., as well as in Hawaii. It occurs from Oregon south to Arizona, and in Texas and several Gulf States to Virginia.

Hardstem Bulrush

Latin Name: Scirpus Acutus

Native to North America, and found from west to east coasts and throughout southern Canada.

Hare Barley

Latin Name: Hordeum Leporinum

Native to Europe, but introduced and now common throughout the western United States.

Harebell

Latin Name: Campanula Spp.

A genus of many dozens of varieties of showy spring flowers, almost all of which are natives in North America. They occur throughout the United States and north to Alaska.

Harvestlice

Latin Name: Agrimonia Parviflora

Native to North America where it is found throughout the eastern half of the United States and into eastern Canada. It is considered a threatened or endangered species in Connecticut and Massachusetts.

Healall

Latin Name: Prunella Vulgaris

A native of Europe, but now widespread throughout the United States and southern Canada.

Hedge-nettle

Latin Name: Stachys Stricta

Native to California, and found widely in the northern half of the state in cool, wet, creekside habitats.

Hemp Dogbane

Latin Name: Apocynum Cannabinum

Native to the United States and occurring throughout the country.

Hemp Sesbania

Latin Name: Sesbania Exaltata

A native plant found commonly throughout the southeast states from Florida to New York, west to Texas, and in California and Arizona.

Henbit

Latin Name: Lamium Amplexicaule

Native to Europe, but now spread throughout North America.

Hilo Grass

Latin Name: Paspalum Conjugatum

Native to tropical America, including the southeastern United States, where it is found from Florida to Texas. It also has been introduced to Hawaii around 1840 and is now a widespread noxious weed there.

Hoary Cress

Latin Name: Cardaria Draba

Introduced from Europe, and now an important pest weed in many crops in California.

Holly

Latin Name: Aquifoliaceae

Honey Locust

Latin Name: Gleditsia Triacanthos

Native to Europe, but widely utilized as an ornamental garden and roadside tree, from which it easily escapes to non-cultivated areas. Now found throughout North America.

Hooker's Evening Primrose

Latin Name: Oenothera Hookeri

Native to the United States.

Horned Rush

Latin Name: Rhynchospora Spp.

There are over 200 species in this genus in the world, with several dozen varieties in the United States.

Horse Purslane

Latin Name: Trianthema Portulacastrum

Native to the United States, where it is found throughout the southern half as well as in Hawaii and the Caribbean.

Horsenettle

Latin Name: Solanum Carolinense

Native to the southeastern United States, but now spread from coast to coast and occurring in almost every state, as well as into southern Canada.

Horseweed

Latin Name: Conyza Canadensis

Native to North America and widely distributed throughout the continent.

Houndstongue

Latin Name: Cynoglossum Officinale

Native to Europe, but now widespread throughout nearly the entire United States and southern Canada. Currently not found in Texas, Florida, or a few other southeastern states.

Hurricane Grass

Latin Name: Fimbristylis Cymosa

Native to Florida and the West Indies, and also found in Hawaii, throughout Latin America, and in the Old World tropics.

Hydrilla

Latin Name: Hydrilla Spp.

Hyssop Loosestrife

Latin Name: Lythrum Hyssopifolium

Native to Europe.

Hyssop Spurge

Latin Name: Chamaesyce Hyssopifolia

Native to the southeastern United States and Latin America, and found in the U.S. Maryland south to Florida, and west to southern California. It also is found in Hawaii and the West Indies.

Iberian Starthistle

Latin Name: Centaurea Iberica

Native to Asia, but introduced to the western United States from Europe, where it now is found along the Pacific Coast states as well as Wyoming and Nebraska.

Indian Tobacco

Latin Name: Nicotiana Bigelovii

Native to the west coast of the United States.

Iris-leafed Rush

Latin Name: Juncus Xiphioides

A native of North America, and found along the Pacific Coast from Canada south to Mexico and east to New Mexico.

Italian Ryegrass

Latin Name: Lolium Multiflorum

A native of Europe, and now widespread throughout the United States.

Italian Thistle

Latin Name: Carduus Pycnocephalus

Native to southern Europe and the Mediterranean area, and now widely found in the western United States.

Ivyleaf Morningglory

Latin Name: Ipomoea Nil

A native of tropical America, now widespread in the United States due to its use as an ornamental planting.

Ivyleaf Speedwell

Latin Name: Veronica Hederaefolia

Native to Europe, and now found along the eastern states of the U.S. from southern Canada into Georgia.

Jamaica Feverplant

Latin Name: Tribulus Cistoides

Native to tropical America, and now found throughout the southeast states west to Texas, in Hawaii, south throughout Latin America, as well as on many other continents.

Japanese Honeysuckle

Latin Name: Lonicera Japonica

Native to eastern Asia but introduced to the United States as an ornamental in the 1800s. It is now naturalized and has escaped cultivation to spread over the entire United States, and is a particularl problem along the east coast states.

Japanese Tea

Latin Name: Chamaecrista Nictitans Patellaria

Native to eastern Asia, but introduced to Hawaii prior to 1870.

Jerusalem Oak Goosefoot

Latin Name: Chenopodium Botrys

A native of Europe and Asia, now widespread in the western U.S., infesting croplands and non-croplands.

Jimsonweed

Latin Name: Datura Stramonium

Native to tropical Americas, but now widely spread throughout the warmer areas of the world, and very common in the southern U.S. but not in the northern Great Plains.

Johnsongrass

Latin Name: Sorghum Halepense

Native to the Mediterranean region, but deliberately introduced to the United States as a grass desirable for forage. Now widespread throughout the warm regions of the U.S. where it is a severe pest weed problem.

Jungle Rice

Latin Name: Echinochloa Colona

Native to Europe, and now widespread throughout the west and southwest United States. Found commonly in both cultivated fields and in waste areas.

Juniper Mistletoe

Latin Name: Phoradendron Juniperinum

Native to western North America, and found from Mexico into Texas, and across the southwest states to Oregon along the Pacific Coast.

Khakiweed

Latin Name: Alternanthera Pungens

A native of tropical America, this weed is widely spread in warm climates. It is found as a common roadside and landscape weed in Hawaii, and also occurs in the southwest United States and across the southern states to Florida, and then sporadically north to Pennsylvania.

Kikuyugrass

Latin Name: Pennisetum Clandestinum

Native to tropical Africa, but introduced deliberately to California as a cover along slopes and ditch banks for erosion control. As a very fast growing grass it also has been used for a turfgrass, but it is capable of escaping and invading other grasses where it is objectionable.

Knawel

Latin Name: Scleranthus Annuus

Introduced from Europe, and found throughout the eastern half of the United States and Canada, as well as in California and the Pacific Northwest.

Knotgrass

Latin Name: Paspalum Distichum

Native to North America, and widely distributed throughout the United States and south into South America.

Knotroot Foxtail

Latin Name: Setaria Geniculata

Native to the United States, where it is found throughout the country from coast to coast, and into South America.

Kochia

Latin Name: Kochia Scoparia

Native to Eurasia, this plant was introduced to North America and now is found in nearly every state, with the exception of the extreme southeast.

Kudzu

Latin Name: Pueraria Thunbergiana

Native to Japan and China, and introduced during an 1896 gardening exposition in Philadelphia.

Ladysthumb

Latin Name: Polygonum Persicaria

Possibly introduced to North America as an ornamental, but so widely spread that it is not known for certain. Now present in all states except Hawaii, and throughout Canada north to Alaska.

Lantana

Latin Name: Lantana camara

A native plant in North America and Latin America, and found widely in warmer climates from North Carolina to Florida and west to California. It also occurs in Hawaii and the West Indies, and south in much of Latin America. It is a common ornamental plant and is spread easily by commerce.

Large Crabgrass

Latin Name: Digitaria Sanguinalis

Native to Europe and now widespread in the United States.

Large Hopclover

Latin Name: Trifolium Campestre

Native to Europe, and now found widespread in the U.S. and north to Canada and Alaska. Not found in the southwestern states.

Lawn Burweed

Latin Name: Soliva Pterosperma

Native to South America, and now found along the Pacific Coast states and along the southern states to North Carolina, as well as throughout Latin America and in Europe.

Lemon Bacopa

Latin Name: Bacopa Caroliniana

Native to the U.S., and found commonly throughout Florida and in surrounding states.

Leopold's Rush

Latin Name: Juncus Acutus Leopoldii

Native to the western United States, where it is present in California, Nevada, and Arizona.

Lesser Butter And Eggs Toadflax

Latin Name: Linaria Supine

Native to Europe, but introduced to the United States as a garden ornamental, and now found in California, Oregon, Idaho, and several states in the area of Pennsylvania.

Lindley's Annual Lupine

Latin Name: Lupinus Bicolor

Native to the western United States, and present as several varieties from California north into Canada.

Lion's Ear

Latin Name: Leonotis Lepetaefolia

A native of tropical Africa, but cultivated as a garden plant and introduced to the United States. It can be found from North Carolina south to Florida and west to Texas, commonly in Hawaii, and in the West Indies.

Little Barley

Latin Name: Hordeum Pussillum

Native to western North America and found as far south as Argentina and throughout most of the U.S. except the northernmost and northeastern states.

Little Bittercress

Latin Name: Cardamine Oligosperma

Native to North America, and found most commonly in the western states, east to Montana and Colorado, but occurring sporadically in the north central to northeast states as well. Found also in western Canada north to Alaska.

Little Mallow

Latin Name: Malva Parviflora

Native to Europe and Asia, now found widespread across the U.S., where it is less commmon than "Common" mallow.

Little Quaking Grass

Latin Name: Briza Minor

Introduced from Europe, and now found throughout the southern half of the United States, north in the east to New York and north in the west to Oregon and Idaho. It also has been introduced to Hawaii.

Little Starwort

Latin Name: Stellaria Graminea

Native to Europe, but introduced to North America, where it now is found throughout the northern two thirds of the United States and in southern Canada.

Littleseed Canarygrass

Latin Name: Phalaris Minor

Native to the Mediterranean region. Widespread in the southwest United States.

Liverworts

Latin Name: Hepaticae

Found throughout North America in excessively moist soils.

Livid Pigweed

Latin Name: Amaranthus Lividus

Native to the Mediterranean, but now found throughout the world. In the United States it occurs along the eastern seaboard states from Vermont to Florida and west to Texas. It also is found in Utah and Hawaii, and in southern Canada.

London Rocket

Latin Name: Sisymbrium Irio

A native of Europe, now common throughout the western states.

Long Beechfern

Latin Name: Phegopteris Connectilis

Native to North America, and found in most states in the upper half of the United States and in southern Canada, from coast to coast.

Long's Sedge

Latin Name: Carex Longii

Native to North America, where it is found throughout the states east of the Mississippi River and west to Texas and Oklahoma. It also is found in Hawaii.

Long-stalked Phyllanthus

Latin Name: Phyllanthus Tenellus

A native of Africa and its nearby islands, but occurring in the United States from Texas to Florida, and north to North Carolina and Tennessee, as well as in Hawaii and the West Indies.

Lyre-leaf Sage

Latin Name: Salvia Lyrata

Native to North America, and found from Texas north to Illinois and east to nearly every state in eastern U.S., as well as south into Mexico.

Many-flower Marsh Pennywort

Latin Name: Hydrocotyle Umbellata

Native to North and South America, and found throughout most of the eastern half of the U.S., as well as along the West Coast.

Marcela

Latin Name: Alternanthera Flavescens

A native plant in Florida as well as Latin America and the West Indies.

Marijuana

Latin Name: Cannabis Sativa

Marsh Bedstraw

Latin Name: Galium Tinctorium

Native to North America, and found throughout the eastern half of the U.S. and Canada, and west to Texas and possibly Arizona.

Marsh Pennywort

Latin Name: Hydrocotyle Spp.

Several varieties, some native to Europe and others native to the United States. They are found throughout the U.S.

Marsh Yellowcress

Latin Name: Rorippa Islandica

Native to North America, and widely distributed throughout the continent up to Alaska.

Marshweed

Latin Name: Limnophila Spp.

Marvel Of Peru

Latin Name: Mirabilis Jalapa

A native of tropical Central and South America, but introduced to the United States as a garden ornamental. This is a prolific producer of seeds, and plants easily escape to become invasive in other areas, now being found throughout the eastern half of the U.S., and west in the southern half to California and Hawaii.

Mayweed Chamomile

Latin Name: Anthemis Cotula

A native of Europe and now common throughout North America, where it is a weed problem in nurseries and landscape, as well as in pastures due to its irritating properties to livestock that graze it.

Meadow Beauty

Latin Name: Rhexia cubensis

Native to the southeastern states of the U.S.

Meadow Knapweed

Latin Name: Centaurea Debeauxii

Native to Europe, but now spread widely throughout the Pacific Northwest and in localized areas of the Northeast U. S.

Medusahead

Latin Name: Taeniatherum Caput-medusae

Introduced from Europe and Asia, now a dominant grass species over widespread rangeland in the western United States, where it crowds out most other grass species. As a grass that is not conducive to grazing it has reduced grazing capacity in some areas up to 75%.

Mexican Pricklypoppy

Latin Name: Argemone Mexicana

Native to the United States, and found throughout most of the eastern half of the U.S., west to Texas and Arizona, and in Hawaii and the West Indies and south into Latin America.

Mexican Sprangletop

Latin Name: Leptochloa Uninervia

Native to the United States, and widespread in this country.

Mexican Whorled Milkweed

Latin Name: Asclepias Fascicularis

Native to Mexico and possibly western United States. Now widely distributed in the west at lower elevations.

Mexicantea

Latin Name: Chenopodium Ambrosioides

Native to Tropical America, now widely distributed in the United States.

Mimosa Vine

Latin Name: Mimosa Strigillosa

A native plant in the United States, occurring in Florida and Georgia west to Texas and Oklahoma and north to Missouri, as well as through Mexico into South America.

Miner's Lettuce

Latin Name: Montia Perfoliata

Native to the western United States and occurring from southern California to British Columbia.

Mojave Pricklypear

Latin Name: Opuntia phaeacantha

Native to the southwest United States and northern Mexico, and found from California east to Texas, Kansas, and South Dakota in arid environments.

Moneywort

Latin Name: Lysimachia Nummularia

Native to Europe, but introduced to North America as a garden plant, and now spread throughout the eastern half of North America as well as along the west coast, and in the central states of Colorado, Kansas, and Nebraska.

Mosquitofern

Latin Name: Azollaceae

Mosses

Latin Name: Musci

Many varieties of mosses that are native to the United States.

Moth Mullein

Latin Name: Verbascum Blattaria

Native of Europe – now widespread in the United States

Mouse-ear Chickweed

Latin Name: Cerastium Vulgatum

Native to Europe, and now found throughout most of the United States and southern Canada.

Myoporum

Latin Name: Myoporaceae

Narrow-leaved Iceplant

Latin Name: Conicosia Pugioniformis

Native to South Africa, but imported as an ornamental plant in California, where it can be found along coastal areas in sandy soils. It spreads rapidly to form dense stands on sand dunes or salt marsh habitats.

Narrowleaf Cudweed

Latin Name: Gnaphalium Falcatum

Native to North America and Latin America, and occurring in the United States from Virginia to Florida on the east coast, and west throughout the southern states to California.

Netseed Lambsquarters

Latin Name: Chenopodium Berlandieri

Native to Europe, and now established in the western United States.

Nettleleaf Goosefoot

Latin Name: Chenopodium Murale

Native to Europe, but naturalized and now widespread in North America.

Nimblewill

Latin Name: Muhlenbergia Schreberi

Native to North America, and found throughout the U.S. from the Midwest to the east coast, into Canada and south into Mexico.

Niruri

Latin Name: Phyllanthus Niruri

Native to Asia, but present now in the tropical regions of most continents. In the United States it occurs from South Carolina and Florida along the Gulf States to Texas and New Mexico, south throughout Latin America, and in Hawaii and the West Indies.

Nodding Spurge

Latin Name: Euphorbia Nutans

Native to the United States, and found throughout the country and south into South America.

Nodding Stipa

Latin Name: Nassella Cernua

A native grass in the western United States, and also in Hawaii.

Northern Bugleweed

Latin Name: Lycopus Uniflorus

Native to North America, and found throughout the upper two thirds of the United States, from California to Georgia, and throughout Canada north to Alaska.

Northern Bush Honeysuckle

Latin Name: Diervilla Lonicera

Native to North America, and found throughout much of the eastern half of the continent.

Northern Willow-herb

Latin Name: Epilobium Ciliatum

Eastern United States – now occurs widely across the U.S.

Nuttall's Thistle

Latin Name: Cirsium Nuttallii

Native to the southeastern United States, where it is found from Virginia south to Florida, and west to Louisiana.

Old World Diamond Flower

Latin Name: Hedyotis Corymbosa

Native to Eurasia, but a serious turf problem in the United States from Texas to Florida, and in many other tropical regions of the world.

Oldfield Cinquefoil

Latin Name: Potentilla Simplex

Native to North America, and found throughout the eastern half of the U.S., with the exception of Florida, and into southern Canada.

Orange Hawkweed

Latin Name: Hieracium Aurantiacum

Native to Europe, but introduced to North America, where it now can be found throughout the northern half of the United States and southern Canada, and south into California, Arkansas, and Florida.

Orchardgrass

Latin Name: Dactylis Glomerata

Native to Eurasia, now widespread throughout much of the United States.

Owl's Clover

Latin Name: Orthocarpus Purpurascens

A native plant that is widely distributed in the western United States, south into Mexico and north into southern Canada.

Oxeye Daisy

Latin Name: Chrysanthemum Leucanthemum

A native of Europe that was introduced as an ornamental plant, this has escaped cultivation and now is found in meadows, roadsides, and empty lots, as well as turf and landscape.

Pacific Poison Oak

Latin Name: Toxicodendron Diversilobum

Native to the United States - spread throughout the western United States, and replaced by Toxicodendron radicans - Poison Ivy - in the eastern half of the country.

Painted Leaf

Latin Name: Poinsettia cyathophora

A native plant in the southeastern United States and Latin America, and through cultivation as an ornamental plant now found throughout the southern half of the U.S., north into the Great Lakes region, and in Hawaii and the West Indies.

Pale Smartweed

Latin Name: Polygonum Lapathifolium

Introduced from Europe.

Paleseed Plantain

Latin Name: Plantago Virginica

Native to the United States, and found from Atlantic to Pacific coasts, south into Mexico, north into Canada, Hawaii, the West Indies and Japan.

Palm

Latin Name: Palmaceae

Palmer Pigweed

Latin Name: Amaranthus Palmeri

Native to the western Unites States, where it occurs widely throughout the western half of the country in the milder climates, and south into Mexico.

Pampas Grass

Latin Name: Cortaderia Selloana

Native to Argentina, but introduced as a landscape plant, and now found in a number of states from Oregon and California east to Florida and north to New Jersey. It does best in warmer climates.

Panicgrass

Latin Name: Panicum Sp.

Some varieties native to North America, and particularly common in the southern tier states.

Panicle Willowweed

Latin Name: Epilobium Paniculatum

Native to the United States.

Pansy

Latin Name: Viola tricolor

Parrotfeather

Latin Name: Myriophyllum Aquaticum

Native to South America, but introduced to the United States and sold as aquatic plants. It was planted in ponds and aquariums and has now spread widely across North America.

Pennsylvania Smartweed

Latin Name: Polygonum Pensylvanicum

Native to eastern North America, and introduced to the western states where it now can be found throughout most of the continent.

Pennywort

Latin Name: Hydrocotyle Spp.

At least 15 species of Hydrocotyle occur in the United States and Hawaii, all very similar in appearance and habits. Most are native plants that occur primarily in warmer, more tropical climates.

Perennial Pepperweed

Latin Name: Lepidium Latifolium

Native to Europe and western Asia, now widely distributed throughout the United States and into Mexico.

Perennial Ryegrass

Latin Name: Lolium Perenne

Native to Europe, but now widely distributed throughout the United States.

Perennial Sowthistle

Latin Name: Sonchus Arvensis

Native to Europe and Asia, this weed is now found coast to coast in the northern United States and southern Canada.

Perez's Sealavender

Latin Name: Limonium Perezii

Native to the Canary Islands, but introduced to North America as a landscape plant. It is found primarily in California.

Persian Speedwell

Latin Name: Veronica Persica

Native to Europe and now widespread in North America.

Peruvian Water Primrose

Latin Name: Ludwigia Peruviana

Native to tropical America, but naturalized in the U.S. where it has become invasive in wet areas in the southeast states.

Petty Spurge

Latin Name: Euphorbia Peplus

A native of Europe, and now distributed from Atlantic Coast to Pacific Coast.

Phasey Bean

Latin Name: Macroptilium Lathyroides

A native plant in the United States, and found in the extreme southeast states and into the West Indies, as well as in Hawaii.

Pickerelweed

Latin Name: Pontederia cordata

A native plant in the United States, and found throughout the eastern half of the country and into Canada and Mexico.

Pine

Latin Name: Pinaceae

Pineapple Weed

Latin Name: Matricaria Matricarioides

Native to the western United States, but now found across the continent to the east coast and as far north as Alaska.

Pink Fuzzybean

Latin Name: Strophostyles Umbellata

Native to North America, and found in Texas north to Missouri, and in nearly all states east of the Mississippi River.

Pink Purslane

Latin Name: Portulaca Pilosa

Native to Florida, but found north to New Jersey and as far west as Nevada. May be used as an ornamental groundcover.

Pink Redstem

Latin Name: Ammannia Latifolia

Native to the United States and Central America, and occurring from Texas to Florida, and north to New Jersey, as well as in the West Indies.

Pink Woodsorrel

Latin Name: Oxalis Martiana

Native to tropical South America, but introduced to other areas as a garden plant. It is found in California, New Mexico, and Hawaii in the U.S.

Platte Thistle

Latin Name: Cirsium Canescens

Native to North America, and distributed from New Mexico north to Idaho, and east to Wisconsin and Ohio. Generally a plant of the north central states.

Poison Hemlock

Latin Name: Conium Maculatum

A native of Europe, but now spread widely and commonly throughout the United States and southern Canada.

Pondweed

Latin Name: Potamogeton Spp.

Native to North America, and found throughout the western states north to Alaska, and in the northern states of the eastern half of the U.S. and into eastern Canada.

Poorjoe

Latin Name: Diodia Teres

Native to North America, and found throughout the eastern half of the U.S. and into Canada, and along the southern states to California.

Powell Pigweed

Latin Name: Amaranthus Powellii

Native to North America, and widespread across the continent, including Mexico.

Prickly Lettuce

Latin Name: Lactuca Serriola

Native to Europe, but now naturalized and found throughout most of North America.

Prickly pear Cactus

Latin Name: Opuntia

Native to North America. Many varieties that have been exported to other parts of the world and have become troublesome.

Prickly Sida

Latin Name: Sida Spinosa

Native to tropical Latin America and southern United States, and found throughout the eastern half of the U.S. and west into Arizona. It also has been introduced to Hawaii as a common roadside weed.

Prostrate Knotweed

Latin Name: Polygonum Arenastrum

Introduced from Europe. Now found throughout the United States and southern Canada.

Prostrate Pigweed

Latin Name: Amaranthus Blitoides

Native to western North America, but now widespread as a common weed throughout the U.S. with the exception of the extreme northern states.

Prostrate Spurge

Latin Name: Chamaesyce Humistrata

Native of the United States, and widely spread across the continent and south into South America

Puncture Vine

Latin Name: Tribulus Terrestris

Native to the Mediterranean area and southern Europe. Now scattered over much of the U.S.

Purple Ammania

Latin Name: Ammannia Coccinea

Native to California.

Purple Aster

Latin Name: Machaeranthera Canescens

Native to the western United States, and widely distributed from Arizona to Utah and along the west coast into southern Canada.

Purple Bushbean

Latin Name: Macroptilium Atropurpureum

Native to the southern United States and Latin America, and introduced to Hawaii prior to 1870. In the U.S. it is found in Arizona, Texas, and Florida.

Purple Cudweed

Latin Name: Gnaphalium Purpureum

Found from South America to North America, where it is found throughout the United States.

Purple Deadnettle

Latin Name: Lamium Purpureum

Native to Eurasia, but now found throughout most of North America up to Alaska.

Purple Loosestrife

Latin Name: Lythrum Salicaria

Native to Europe, but introduced as an ornamental plant to North America, where it now occurs in nearly every state in the U.S. with the exception of the arid Southwest and the extreme Southeast. It also occurs throughout most of Canada.

Purple Nutsedge

Latin Name: Cyperus Rotundus

Native to Europe, but now thoroughly spread around the world on all continents. In North America it is found primarily in the southern states from California to Florida, and north to Missouri and New York, as well as a few other states. It occurs in the West Indies, Hawaii, and throughout Latin America.

Purple Passionflower

Latin Name: Passiflora Incarnata

Native to the southeastern United States, and found from Texas to Florida, north to Illinois and Pennsylvania.

Purple Sedge

Latin Name: Cyperus Ligularis

Native to southeastern United States and the West Indies, and found in Florida, Mississippi, California, and Latin America, as well as in Africa.

Purple Starthistle

Latin Name: Centaurea Calcitrapa

Native to Europe but introduced to the United States, where it now can be found in the western U.S. from Washington to California and east to New Mexico, as well as in scattered Midwest and Atlantic Coast states and in Mississippi.

Purple Vetch

Latin Name: Vicia Benghalensis

Native to Europe, and currently found as an escape from cultivation in much of California and in New York. Found along roadsides, in disturbed sites, and wooded areas, similar to other vetch species.

Purslane Speedwell

Latin Name: Veronica peregrina

Native to the United States, and found throughout the U.S.

Quackgrass

Latin Name: Agropyron Repens

Introduced from Europe and now found throughout most of the United States, with the exceptions of the warm southern areas from South Carolina to Arizona.

Rabbit's Paw

Latin Name: Thelechitonia Trilobata

Native to tropical America, and found in Latin America, but used as an ornamental groundcover and sold throughout the warmer areas of the United States as well as in Hawaii.

Rabbitfoot Clover

Latin Name: Trifolium Arvense

A native of Europe, but introduced to North America where it now occurs throughout the eastern half of the United States, all of southern Canada, and in the western U.S. along the Pacific Coast and in the states bordering Canada. It also occurs in Hawaii.

Rabbitfoot Polypogon

Latin Name: Polypogon Monspeliensis

Native to southern and western Europe, now widespread in the United States.

Radiate Fingergrass

Latin Name: Chloris Radiata

Native to tropical America and Florida, but introduced to Hawaii and the Pacific Northwest.

Rat-tail Fescue

Latin Name: Vulpia Myuros

Introduced from Europe, and now found throughout the United States, in southern Canada and Latin America, as well as in Alaska and Hawaii. V. myuros and F. megalura are sometimes separated as two species, but currently combined as only one.

Rattlebush

Latin Name: Sesbania Punicea

Native to South America, but commonly used as an ornamental plant, and now escaped from cultivation and common in many other parts of the world. It is a particularly noxious weed in South Africa. In the United States it can be found in California, and from Texas east to Florida and north to Virginia.

Rattlesnake Mannagrass

Latin Name: Glyceria Canadensis

Native to North America, and found in southern Canada, and in the United States in the Pacific Northwest, north Central, and northeast states.

Red Clover

Latin Name: Trifolium Pratense

Native to Eurasia, but introduced as a pasture plant which has escaped cultivation and is now widespread in the United States.

Red Oxalis

Latin Name: Oxalis Rubra

Native to South America, but introduced as an ornamental plant, and now escaped from cultivation to be an invasive weed in California, and from Texas east to Florida and north to Virginia. Generally found around urban areas.

Red Sandspurry

Latin Name: Spergularia Rubra

Introduced from Europe, and now found throughout the western half of North America to Alaska, and in the northeastern quarter of the U.S. and into eastern Canada.

Red Sorrel

Latin Name: Rumex Acetosella

Native to Europe, now distributed widely across the United States and southern Canada.

Red Spiderling

Latin Name: Boerhavia Diffusa

Native to southeastern United States, and found sporadically from North Carolina south to Florida, and west to Texas and California. It also is found in Hawaii, the Caribbean, and south through Latin America.

Red Sprangletop

Latin Name: Leptochloa Filiformis

Native to tropical Latin America.

Redroot Flatsedge

Latin Name: Cyperus Erythrorhizos

A native sedge in North America, and found in all states and southern Canada.

Redroot Pigweed

Latin Name: Amaranthus Retroflexus

Native to tropical Latin America, but now widespread in the United States.

Redstem Filaree

Latin Name: Erodium cicutarium

Native to Europe and Asia, now common throughout the world.

Reed Canarygrass

Latin Name: Phalaris Arundinacea

Native to Eurasia, and now found throughout the northern United States and Canada.

Rescuegrass

Latin Name: Bromus Catharticus

Native to South America, and introduced to the United States for cultivation as a winter forage in the southern states. Strong growth in winter and early spring make it suitable for forage. It commonly escapes cultivated areas and becomes troublesome in crops or non-crop situations.

Ripgut Brome

Latin Name: Bromus Diandrus

Native to Europe, and now widespread along the Pacific Coast states. It is a very common weed species in rangeland, roadsides, waste areas, or ditchbanks, where it may compete with native plants.

River Bulrush

Latin Name: Scirpus Fluviatilis

Naturalized in the United States and found throughout temperate North America, as well as in much of Asia and into New Zealand.

Rock Fingergrass

Latin Name: Chloris Petraea

A native grass in the United States and Latin America, and found in Pennsylvania, the southeast states and in Hawaii and the West Indies.

Rough Cinquefoil

Latin Name: Potentilla Norvegica

Native to North America, and present throughout the continent and north to Alaska.

Rough Fleabane

Latin Name: Erigeron Strigosus

Native to North America, and found throughout southern Canada and all states of the U.S. except for some of the dry Southwest states.

Roughseed Bulrush

Latin Name: Scirpus Mucronatus

Native to Eurasia, but accidentally introduced to the rice-growing regions of California, and now a widespread weed in marshy habitats in California.

Roughseed Buttercup

Latin Name: Ranunculus Muricatus

Native to Europe, but common along the West Coast and found to the Atlantic Coast.

Roughstalk Bluegrass

Latin Name: Poa Trivialis

Introduced from Europe as a forage grass, and present throughout much of North America to Alaska. It also is used occasionally for turf in wet habitats, but does not tolerate dry conditions and thus is limited in its use as a turf grass.

Roundleaf Geranium

Latin Name: Geranium rotundifolium

Introduced from Europe as a garden herb, and now found sporadically across the United States.

Rush Skeletonweed

Latin Name: Chondrilla Juncea

A native of Eurasia and introduced as an ornamental plant. It spreads rapidly and now infests millions of acres in the western United States.

Russian Knapweed

Latin Name: Acroptilon Repens

A native of Eurasia that was introduced to the United States in the late 1800’s, and now is widely distributed over the western U.S.

Russian Olive

Latin Name: Elaeagnus Angustifolia

Introduced from Europe as a desirable ornamental shade tree and source of food for wildlife. Now found throughout the U.S. except for the southeast states, and listed as a noxious and invasive weed species in many states.

Russian Thistle

Latin Name: Salsola Tragus

Native to Eurasia, but introduced to the United States from Russia in sacks of flaxseed, that spilled along railways as it was transported, spreading the weed throughout the western U.S.

Rustweed

Latin Name: Polypremum Procumbens

Native to North America, and found throughout most of the eastern United States, from Colorado to New York and south to Florida and Texas, as well as throughout Latin America.

Sacred Thornapple

Latin Name: Datura Wrightii

Native to the western United States.

Saltcedar

Latin Name: Tamarix Ramosissima

Native to Eurasia and introduced to the United States as an ornamental plant. Now found widespread in the U.S.

Saltgrass

Latin Name: Distichlis Spicata

Native to the western United States.

Salvinia

Latin Name: Salviniaceae

Sand Pigmyweed

Latin Name: Crassula connata

Native to Chile and now widely distributed along the west coast in California and Oregon.

Sargent's Catchfly

Latin Name: Silene Sargentii

A native perennial that is found sporadically in the western U.S., in California and Nevada.

Saw Greenbrier

Latin Name: Smilax Bona-nox

Native to North America, and found from Texas to Florida, and north to Illinois and New York.

Scarlet Pimpernel

Latin Name: Anagallis Arvensis

Scarlet Pimpernel Blue Form

Latin Name: Anagallis Arvensis

Introduced from Europe, and now distributed across all of the United States, but a particular problem along the Atlantic states and Pacific Coast states.

Sea Purslane

Latin Name: Sesuvium Portulacastrum

Native to North America, and found as a desirable plant along coastal sand dunes and beaches, but also with the ability to grow extensively in nearby sandy areas where it may not be wanted. Found in the U.S. from Texas to Florida, north to Massachusetts, and in Hawaii and the Caribbean.

Sea Rocket

Latin Name: Cakile Edentula

Native to North America, and found primarily along coastal shore areas. It occurs in all states along the Pacific and Atlantic coasts, north to Alaska, and inland in states surrounding the Great Lakes.

Sensitive Pea

Latin Name: Chamaecrista Nictitans

Native to North America, and found from Arizona east to Louisiana and Missouri, and in every state east of the Mississippi River.

Sensitive Plant

Latin Name: Mimosa Pudica

Native to tropical areas of North and South America, but now spread widely throughout the world. It is found in Florida and a few coastal states north of Florida, as well as commonly in Hawaii and the West Indies.

Sharppoint Fluvellin

Latin Name: Kickxia Elatine

Native to Europe, but introduced to the U.S., where it now is found along the West Coast and throughout the eastern half of the country.

Shepherd's Purse

Latin Name: Capsella Bursa-pastoris

Native to Eurasia, but now found throughout North America as far north as Alaska.

Showy Evening Primrose

Latin Name: Oenothera Speciosa

Native to the southern United States, but sold as a drought resistant garden ornamental and groundcover throughout the U.S., from which it commonly escapes to other habitats.

Showy Milkweed

Latin Name: Asclepias Speciosa

Native to the United States, and widespread in the western states.

Showy Rattlebox

Latin Name: Crotalaria Spectabilis

Native to the Indo-Malaysian region, but often planted as an ornamental. It is now found throughout the southeast third of the U.S. north into Illinois, as well as in the Caribbean and Hawaii. It also is found on other Pacific Islands, where it is considered a noxious weed and a threat to native ecosystems.

Shyleaf

Latin Name: Aeschynomene Americana

A native plant in North America, where it is found in Florida and surrounding southeastern states, as well as in the West Indies.

Sibara

Latin Name: Sibara Virginica

Native to North America, and found throughout the southeastern states from Nebraska to Maryland, south to Florida and west to Texas, as well as in California and south into Mexico.

Silk Tree

Latin Name: Albizia Julibrissin

Native to a wide area of Asia, but introduced as a garden ornamental, and now found widely throughout the southern half of the United States, into Mexico, and north along the east coast to New York.

Silverleaf Nightshade

Latin Name: Solanum Elaeagnifolium

Native to the central United States, but introduced to the western states where it now is widespread in southern and central California.

Silversheath Knotweed

Latin Name: Polygonum Argyrocoleon

Native to southwest Asia

Silvery Cinquefoil

Latin Name: Potentilla Argentea

Native to Europe, but possibly introduced to North America as a garden plant. It now is present across the northern half of the United States and southern Canada.

Skeletonleaf Bursage

Latin Name: Ambrosia Tomentosa

Native to the Great Plains in the U.S., and found from Wisconsin and Illinois west to Idaho and Arizona.

Slender Fimbry

Latin Name: Fimbristylis Autumnalis

A native plant in the eastern half of North America, where it occurs in every state east of the Rocky Mountains and in eastern Canada, in California, and south into Latin America.

Slender Sandbur

Latin Name: Cenchrus Gracillimus

Native to North America, and found in the extreme southeast states and in Puerto Rico.

Slender Speedwell

Latin Name: Veronica Filiformis

Native to Eurasia, but introduced to the United States as an ornamental plant, and now is widespread in the northern states, from coast to coast.

Slim Aster

Latin Name: Aster Subulatus

A native plant found throughout much of North America.

Small Eyebane

Latin Name: Chamaesyce Nutans

Native to eastern North America and found throughout the eastern two thirds of the United States, as well as in California and the Caribbean.

Smallflower Buttercup

Latin Name: Ranunculus Abortivus

Native to North America, and occurring from Alaska through Canada to most of the United States.

Smallflower Geranium

Latin Name: Geranium pusillum

Native to Europe, and found throughout the United States and southern Canada.

Smallseed Falseflax

Latin Name: Camelina Microcarpa

A native of Europe, now widespread in the United States.

Smooth Crabgrass

Latin Name: Digitaria Ischaemum

Native to Europe and now widespread in the United States.

Smooth Crotalaria

Latin Name: Crotalaria Pallida Var. Obovata

An introduced plant, native to Latin America, and now found in the southeastern U.S., Hawaii, and the West Indies.

Smooth Pigweed

Latin Name: Amaranthus Hybridus

Introduced from tropical Latin America, and now widespread in the United States.

Smooth Scouring-rush

Latin Name: Equisetum laevigatum

A native of the United States, distributed widely in California.

Smooth Water Hyssop

Latin Name: Bacopa Monnieri

Native to the southeastern states of the U.S., and found from Florida to California in the southern half of the United States, as well as in Hawaii and the West Indies.

Smutgrass

Latin Name: Sporobolus Spp.

Native to the southeastern U.S. and into Latin America, and found throughout the eastern and Midwestern states and west to California.

Soft Brome

Latin Name: Bromus Hordeaceus

Native of Eurasia, introduced from Europe, and widespread in the western United States. Winter growth serves as livestock forage in some areas.

Soft Rush

Latin Name: Juncus Effusus Var. Pacificus

Sour Grass

Latin Name: Digitaria Insularis

Native to tropical Americas including the southern United States, where it is present from Florida to Texas, as well as in Illinois and New Mexico. It was introduced to Hawaii in the early 1900’s and has become a noxious weed problem there.

Southern Catalpa Tree

Latin Name: Catalpa Bignonioides

Native to the Gulf states of North America, but sold widely as a garden ornamental tree. It is a prolific seed producer, and commonly escapes cultivation to grown along roadsides, in vacant lots, or other disturbed sites, generally where water is available. Found throughout the eastern half of the U.S., along the Pacific Coast, and in Arizona, New Mexico, and North Dakota.

Southern Fleabane

Latin Name: Erigeron Quercifolius

Native to the southeastern United States and the West Indies, and occurring from Virginia south to Florida and west to Louisiana and Arkansas.

Southern Naiad

Latin Name: Najas Guadalupensis

Southern Pencil-flower

Latin Name: Stylosanthes Hamata

A native plant in Florida, and found also in the West Indies.

Southern Sandbur

Latin Name: Cenchrus Echinatus

Found throughout the southern half of the U.S. from the east coast to New Mexico, south throughout Latin America, in Hawaii, as well as Africa and parts of Asia.

Southern Sida

Latin Name: Sida Acuta

Native to the United States, and found from Texas along the Gulf States to South Carolina, as well as in a few Northeast states, Hawaii, and the West Indies. It is also in Central America and Africa.

Southwestern Cupgrass

Latin Name: Eriochloa Gracilis

Native to the southwestern United States.

Spanish Broom

Latin Name: Sparteum Junceum

Native to the Mediterranean region, but introduced to many other continents, and found widely along the west coast of the United States and southern Canada. It also has been introduced to Hawaii.

Spanish Clover

Latin Name: Lotus Purshianus

Native to the western United States, and widely distributed from southern Canada south into Mexico in the west.

Spanish Needles Beggarticks

Latin Name: Bidens Pilosa

Native to Latin America, but introduced to the United States, where it now is found throughout the southern third of the country from California to Florida, and north to Pennsylvania. It also is found in Hawaii and the West Indies.

Spearmint

Latin Name: Mentha Spicata

Native to Europe, but introduced as an herb for its fragrance and as an additive in recipes. Widespread in the United States.

Spikerush

Latin Name: Eleocharis Sp.

Both native and introduced species.

Spikeweed

Latin Name: Hemizonia Pungens

Native to the central valley of California, and now spread throughout the southern state as well as into Oregon and Washington.

Spiny Cocklebur

Latin Name: Xanthium Spinosum

Introduced from Europe and now found from the Atlantic to the Pacific coasts, as well as in many other parts of the world in warmer climates.

Spiny Pigweed

Latin Name: Amaranthus Spinosus

Native to North America, but introduced to Hawaii as well. In the United States it is found in California and throughout the eastern half of the country, north into southern Canada and south through much of Latin America and the West Indies.

Spiny Sowthistle

Latin Name: Sonchus Asper

Native to Europe and Asia, and now widely distributed throughout North America.

Spotted Joepyeweed

Latin Name: Eupatorium Maculatum

Native to North America, and found throughout the northern half of the United States, south into Arizona and New Mexico, and throughout southern Canada.

Spotted Knapweed

Latin Name: Centaurea maculosa

Accidentally introduced from Europe as a contaminant in crop seeds, and now one of the major weed pests on rangeland in Montana. It is found throughout the northern half of the United States

Spotted Spurge

Latin Name: Chamaesyce Maculata

Native to the United States, and now widely spread across the continent and south into South America.

Spotted Water-hemlock

Latin Name: Cicuta Maculata

Native to North America and found throughout much of the United States and southern Canada.

Sprawling Horseweed

Latin Name: Calyptocarpus Vialis

Native to tropical America and introduced into the United States, where it now can be found from South Carolina and Florida west to New Mexico, in Illinois and in Hawaii.

Spreading Dayflower

Latin Name: Commelina Diffusa

Native to the southeastern United States and Latin America, and found in the U.S. from New England south throughout Florida, west to Texas and Kansas, and in Hawaii and the West Indies. It also is found throughout Latin America as well as in tropical countries in Africa and Asia.

Spreading Dogbane

Latin Name: Apocynum Androsaemifolium

Native to North America, and found throughout the western states, Canada, and into the northeast United States.

Spreading Prickly-pear

Latin Name: Opuntia Humifusa

Native to North America, and found widely throughout the eastern half of the country and into southern Canada and Mexico.

Spurred Anoda

Latin Name: Anoda Cristata

A native of the southwest United States. Having spread throughout the west it now is a noxious weed in landscape, crops, ditch banks, and roadsides.

Squirreltail Grass

Latin Name: Elymus Elymoides

A native of western North America, where it occurs in every state from Texas north to North Dakota and west to the Pacific Coast, north into Canada and south into Mexico. It also may extend east into West Virginia.

Staghorn Sumac

Latin Name: Rhus Typhina

A native shrub or tree that is found throughout the eastern U.S. and Canada, and west in a few states to Utah.

Star Of Bethlehem

Latin Name: Ornithogalum Umbellatum

Native to Europe, but found in many continents, including in Canada, the southern United States, and Hawaii.

Star-rush Whitetop

Latin Name: Rhynchospora Colorata

Native to the Unites States, and found throughout the southeast from Texas to Florida and north to Virginia, as well as in Puerto Rico.

Starwort

Latin Name: Callitriche

Sticky Chickweed

Latin Name: Cerastium Glomeratum

Native to Europe, and now found throughout the United States.

Sticky Madia

Latin Name: Madia Gracilis

Native to western North America, where it occurs from California north into Canada, and east to Montana and Utah. It also occurs as an introduced species in Maine.

Stinging Nettle

Latin Name: Urtica Dioica

Urtica dioica var. dioica is native to Europe, but U. dioica var. procera is the common North American variety and is considered naturalized.

Stinkgrass

Latin Name: Eragrostis Cilianensis

Introduced from Eurasia, now found throughout the United States.

Stinkwort

Latin Name: Dittrichia Graveolens

Native to the western United States.

Sturdy Bulrush

Latin Name: Scirpus Robustus

Native to western United States, where it can be a common weed in California in wet habitats.

Subterranean Clover

Latin Name: Trifolium Subterraneum

Native to Europe and introduced to the United States, where it now is found along the Pacific Coast, and from Louisiana along the Gulf States to Florida and sporadically north along the Atlantic Coast.

Sulfur Cinquefoil

Latin Name: Potentilla Recta

Introduced from Europe and now spread throughout the United States and Canada, with the exception of the dry southwestern U.S.

Summer Lupine

Latin Name: Lupinus Formosus

Native to the west coast states of the United States, and widely distributed as 3 varieties. Occurs from Washington to southern California.

Surinam Sedge

Latin Name: Cyperus Surinamensis

Native to the southeastern United States, and found from Florida and South Carolina west to Texas and Oklahoma, as well as in the West Indies and throughout Latin America.

Swamp Milkweed

Latin Name: Asclepias Incarnata

Native to North America, and found throughout southern Canada and the United States with the exception of the states along the west coast.

Swamp Morningglory

Latin Name: Ipomoea Aquatica

Native to tropical Africa and southern Asia, and an introduced weed in the United States in Florida and Hawaii.

Swamp Pricklegrass

Latin Name: Crypsis Schoenoides

Native to Eurasia and Africa, but now occurring in the western U.S. from Arizona to Idaho and along the Pacific Coast.

Swamp Smartweed

Latin Name: Polygonum Amphibium

Native to Eurasia, and now found throughout much of North America.

Sweet Fern

Latin Name: Comptonia Peregrina

Sweet Scent

Latin Name: Pluchea Odorata

Native to the eastern United States, but also an introduced exotic species in Hawaii.

Sweet Vernalgrass

Latin Name: Anthoxanthum Odoratum

Native to Europe, and now spread widely across the U.S. , south through Latin America, and in Asia and Australia.

Swinecress

Latin Name: Coronopus Didymus

A native of Europe, now found throughout the United States.

Tall Buttercup

Latin Name: Ranunculus Acris

Introduced from Europe and now established throughout much of North America, where it is a common spring wildflower in meadows and along roadsides.

Tall Fescue

Latin Name: Festuca Arundinacea

Introduced from Europe, and now widely distributed throughout the United States.

Tall Fimbry

Latin Name: Fimbristylis Dichotoma

Native to the southeastern United States, and present from Texas along the Gulf Coast states to Florida, and north to Virginia. It also has been introduced into Hawaii.

Tall Morningglory

Latin Name: Ipomoea Purpurea

Native to tropical America, and widespread in the United States due to its use as an ornamental vine.

Tall Vervain

Latin Name: Verbena Bonariensis

A native of South America, now a common weed in much of California, where it favors habitats of high moisture along ditch banks or roadsides, as well as stream beds that dry up in the summer.

Tatarian Honeysuckle

Latin Name: Lonicera Tatarica

Native to Europe, but introduced to the United States as a garden ornamental, and it has escaped cultivation to become an invasive plant throughout the northern U.S. and southern Canada west to Montana and north to Alaska, as well as being found in California.

Telegraph Plant

Latin Name: Heterotheca Grandiflora

Native to southern California, and found throughout much of this state.

Texas Sedge

Latin Name: Cyperus Polystachyos

Native to southeastern United States and Latin America, but found throughout the world in tropical habitats. In the U.S. it is found from Maine to Florida, west to Texas and Missouri, and in Hawaii. It also is in the West Indies, Asia, and Europe.

Threebract Loosestrife

Latin Name: Lythrum Tribracteatum

Native to Europe, but introduced to the western United States, where it occurs sporadically in California, Idaho, and Utah.

Threeflower Beggarweed

Latin Name: Desmodium Triflorum

Possibly a native in the United States, where it occurs in Florida. It also occurs in Hawaii, throughout the West Indies and Latin America, and on most other continents. Some literature states it is native to Eurasia.

Threelobe False Mallow

Latin Name: Malvastrum Coromandelianum

Native to Latin America, and introduced to the southern United States and Hawaii. In the U.S mainland it occurs from Texas east to Florida, and sporadically north to Pennsylvania.

Tievine

Latin Name: Ipomoea Cordatotriloba

Native to the United States, and found from Texas east to South Carolina and Florida.

Timothy

Latin Name: Phleum pratense

Native to Eurasia, but introduced as a forage crop and cultivation for hay. Now escaped and naturalized throughout most of North America.

Tiny Bluet

Latin Name: Houstonia Pusilla

Native to North America, and found widely in nearly all states east of the Rocky Mountains with the exception of the extreme northern tier.

Tomatillo Groundcherry

Latin Name: Physalis Philadelphica

Often grown in gardens for its fruit, and now escaped from cultivation to become a problem in crops, orchards, and other areas.

Toothed Dock

Latin Name: Rumex Dentatus

Introduced from its native Europe and Asia, and now found in most western states and in several Midwest states, such as Illinois and Missouri.

Toothed Spurge

Latin Name: Euphorbia Dentata

Native to the United States, and found from the Atlantic Coast states to Arizona, and possibly into southern California.

Torpedograss

Latin Name: Panicum Repens

Thought to have originated in Europe, but now found on most continents and in the U.S. from the Carolinas along the Gulf states to Texas.

Tower Mustard

Latin Name: Arabis Glabra

Native to North America, where it occurs from Alaska throughout Canada, and in the U.S. in nearly every state with the exception of the southeast states from Texas to South Carolina.

Tread Softly

Latin Name: Cnidoscolus Stimulosus

Native to the United States, where it is found from West Virginia and Virginia south to Louisiana and Florida.

Tree Tobacco

Latin Name: Nicotiana Glauca

Native to South America, but now widespread in the southwest states. Tolerant of dry conditions, but also found along ditch banks and streams, roadsides, and in cultivated crops.

Tree-of-Heaven

Latin Name: Ailanthus Altissima

Native to Eastern Asia and introduced as an ornamental garden plant. Now escaped and a growing problem in empty lots, roadsides, and waste areas in California.

Tropical Whiteweed

Latin Name: Ageratum Conyzoides

Native to tropical North and Latin Americas, and occurring in the United States in Hawaii, California, and the southeastern states from Missouri to Florida. It also occurs sporadically northward along the east coast.

Trumpet-creeper

Latin Name: Campsis Radicans

Native to the eastern half of the United States, but sold as a landscape ornamental and now found throughout the U.S.

Tufted Knotweed

Latin Name: Polygonum Caespitosum

Native to Asia, and now found along the entire east coast of the United States, south through Florida and west to Louisiana.

Tufted Kyllinga

Latin Name: Kyllinga Pumila

Native to North America, and found throughout most of the eastern half of the U.S. from Kansas and Texas east to New York and Florida, and south throughout Latin America and the West Indies.

Tumble Mustard

Latin Name: Sisymbrium altissimum

Native to Europe, but now found throughout North America in nearly all states of the U.S., including Alaska and Hawaii.

Tumble Pigweed

Latin Name: Amaranthus Albus

Native to tropical Americas, and now widespread throughout much of North America.

Turkey Mullein

Latin Name: Eremocarpus Setigerus

A native of the western United States, and found commonly from southern California north to Washington, particularly in the more arid locations away from the coast.

Twinflower

Latin Name: Dyschoriste Oblongifolia

Native to the southeast United States, occurring from Mississippi to Florida and north to Virginia. This is considered a wildflower and generally is not a noxious weed.

Umbrella Sedge

Latin Name: Cyperus Alternifolius

A native of Africa, and introduced and used commonly as a landscape planting. Not a particular weed problem, but it has escaped cultivation and will be found along some roadsides or waste areas.

Unicellular Blue-Green Algae

Latin Name: Chroococcales

Uruguay Water Primrose

Latin Name: Ludwigia Hexapetala

Introduced from South America, likely as an ornamental plant, and now established along the west coast of the U.S., and from Texas and Missouri east to Florida and north to New York along the east coast.

Valley Popcorn Flower

Latin Name: Plagiobothrys Canescens

Native to the west coast of the United States, and widely distributed throughout California.

Variable Flatsedge

Latin Name: Cyperus Difformis

Native to tropical regions of Eurasia, but now spread to many other areas of the world. In the United States it occurs from California along the southern states to Florida and north to Pennsylvania, as well as in Hawaii and Puerto Rico.

Vaseygrass

Latin Name: Paspalum Urvillei

Native to South America, but introduced as a forage plant, and now spread throughout the southern half of the U.S. from Virginia to California.

Velvetleaf

Latin Name: Abutilon Theophrasti

Native to southern Asia, but introduced to the United States as an ornamental plant and now found throughout the U.S., southern Canada, and into Latin America as an escape from cultivation.

Venice Mallow

Latin Name: Hibiscus Trionum

Native to Europe and Africa, but imported to North America where it now can be found in virtually all of the contiguous states. A state-listed noxious weed in several states.

Ventenata

Latin Name: Ventenata Dubia

Native to Eurasia, widespread in the western United States. A common grass that grows in almost any situation as a low, dense cover. Once it’s seed panicles emerge it becomes useless as a forage grass, with seeds that have sharp, stout awns.

Vervain, Blue

Latin Name: Verbena hastate

A native North American plant, occurring in nearly every state in the United States, and into Canada and Mexico.

Vervain, Jamaica

Latin Name: Stachytarpheta jamaicensis

Native to tropical North and Latin Americas, and found in the United States in Florida and Alabama. It also has been introduced to Hawaii, where it is an extremely common roadside weed.

Vervain, prostrate

Latin Name: Verbena bracteata

A native weed in North America, and found throughout virtually every state in the U.S., in southern Canada and south into Latin America.

Vinegarweed

Latin Name: Trichostema Lanceolatum

Native to the west coast of the United States, and distributed throughout California and into southern Canada.

Virgate Tarweed

Latin Name: Holocarpha Virgata

A native plant in California, and extremely common in pastures, disturbed sites, and along roadsides. Also found in Oregon.

Virginia Buttonweed

Latin Name: Diodia Virginiana

Native to the United States, and found from Texas north to Illinois, east to the Atlantic coast and south to all the Gulf Coast states.

Virginia Creeper

Latin Name: Parthenocissus Quinquefolia

Native to the eastern United States, but common throughout the U.S. in gardens and as an escape in wooded areas.

Virginia Dwarf Dandelion

Latin Name: Krigia Virginica

Native to eastern North America, and found in nearly every state in the eastern half of the country and into eastern Canada.

Virginia Groundcherry

Latin Name: Physalis Virginiana

Native to the western United States.

Virginia Pepperweed

Latin Name: Lepidium Virginicum

Native to the east coast of North America, and now found throughout much of the U.S.

Wall Bedstraw

Latin Name: Galium Parisiense

Native to the Mediterranean region.

Wandering Cudweed

Latin Name: Gnaphalium Pensylvanicum

A native plant in North America, and found in the United States from Pennsylvania south to Florida, and west to Texas. It also occurs in California.

Water Arum

Latin Name: Calla Palustris

Native to North America, and found in the northeastern U.S. from Maine to North Dakota, and north through Canada to Alaska.

Water Buttercup

Latin Name: Ranunculus Spp.

Water Hyacinth

Latin Name: Eichhornia Crassipes

Native to Latin America, and thought to have been introduced to the United States as an ornamental plant. Now present throughout the milder climates of the U.S., from Florida to California, where it can be a severe problem in navigable waterways and irrigation canals, where its thick, smothering growth obstructs movement and water flow.

Water Lettuce

Latin Name: Pistia stratiotes

Water Speedwell

Latin Name: Veronica Anagallis-aquatica

Native to Europe but introduced to North America, and found in nearly every state, in Mexico south into South America, and north throughout Canada to Alaska.

Watermilfoil

Latin Name: Myriophyllum Spp.

Western Goldenrod

Latin Name: Solidago Occidentalis

Native to the western United States, and present from Nebraska and Texas west to the Pacific Coast and north to southern Canada.

Western Ragweed

Latin Name: Ambrosia Psilostachya

Native to the western United States, and found from Mexico to southern Canada and as far east as Illinois.

Western Salsify

Latin Name: Tragopogon Dubius

Native to Europe, but now found throughout most of the United States, particularly in the western states but increasing in occurrence in the northeast states.

Western Thimbleberry

Latin Name: Rubus Parviflorus

Native to the western United States, and found throughout the Pacific states to the Rocky Mountain states, found in some North Central states of the U.S. and into Canada, and populations exist in the New England area.

Western Wild Cucumber

Latin Name: Marah Oreganus

Native to the western United States and Canada.

White Campion

Latin Name: Silene Alba

Native to Europe, and introduced to North America as a garden plant. It easily escapes cultivation and now is found throughout the United States with the exception of the extreme southern states, and throughout Canada north to Alaska.

White Clover

Latin Name: Trifolium Repens

Native to Europe, but introduced as an ornamental and forage plant, and now found commonly throughout North America. It is a weed in turf grasses and landscape, as well as in many crop settings. It tolerates close mowing and becomes a problem by outcompeting the turf.

White Horehound

Latin Name: Marrubium Vulgare

A native of Europe, but probably introduced to the United States as a garden herb and now widely distributed in the U. S.

White Kyllinga

Latin Name: Kyllinga Nemoralis

Native to Asia, and introduced to Hawaii, where it is a common turf weed, and even may be used as a turf substitute in some situations.

White Leadtree

Latin Name: Leucaena Leucocephala

Native to tropical areas of the United States and Latin America, and present as an introduced plant in Hawaii. In the U.S. it occurs sporadically in Arizona, Texas, and the southeast.

White Mulberry

Latin Name: Morus Alba

Native to China, but so widely used as an ornamental tree that it is now spread throughout the world.

White Sweetclover

Latin Name: Melilotus Alba

Native to Eurasia, but introduced as cover crops and nectar sources, and now widespread across much of the United States and into southern Canada.

Whitehead Broom

Latin Name: Spermacoce Verticillata

Native to tropical America, this weed was introduced to the United States, where it now is found in Florida and Texas, as well as in the West Indies, Africa, and on Pacific islands.

Whiteheath Aster

Latin Name: Aster Pilosus

Native to eastern North America, and found along the east coast and west to Minnesota and Nebraska, as well as in southern Canada.

Whitestem Filaree

Latin Name: Erodium moschatum

Native to the Mediterranean, now widespread in the U.S.

Wild Basil

Latin Name: Clinopodium Vulgare

Native to North America, and found sporadically throughout many states from coast to coast.

Wild Bergamot

Latin Name: Monarda Fistulosa

Native to North America, and found throughout Canada and the United States, with the exception of the west coast and Florida. It may occur in Oregon.

Wild Buckwheat

Latin Name: Polygonum Convolvulus

Introduced from Europe, and now widespread throughout the United States and southern Canada.

Wild Caraway

Latin Name: Carum Carvi

Introduced from Europe, and now an escape from cultivation in the western United States.

Wild Carrot

Latin Name: Daucus Carota

Native to Europe and introduced as a garden plant. It escaped cultivation and is now a common and problem weed throughout North America.

Wild Celery

Latin Name: Apium Leptophyllum

Native to South America, and now found widespread in the western states, southeast to Florida and the West Indies.

Wild Cucumber

Latin Name: Echinocystis Lobata

Native to North America, and found throughout nearly the entire United States and southern Canada.

Wild Garlic

Latin Name: Allium Vineale

Native to Europe, but now found throughout the eastern half of the United States, along the Pacific Coast, in Canada, as well as Africa.

Wild Grape

Latin Name: Vitis Spp.

Most are native to the United States and occur in most regions of the U.S.

Wild Hyacinth

Latin Name: Dichelostemma Pulchellum

Native to the western United States, and found along the Pacific Coast and east to Utah and Arizona.

Wild Licorice

Latin Name: Glycyrrhiza Lepidota

Native to the western United States, and found from southern Canada south into Mexico.

Wild Mint

Latin Name: Mentha Arvensis

Native to North America, and found throughout the U.S. and Canada to Alaska, with the exception of the extreme southeast states.

Wild Mustard

Latin Name: Brassica Kaber

Native to Eurasia, and now found throughout the United States.

Wild Oats

Latin Name: Avena Fatua

Native to Europe, now widespread in the United States, being most common in the western half of the country. In California it is the most widespread and noxious of the winter annual grass weeds.

Wild Radish

Latin Name: Raphanus Sativus

Native to Europe, and now widespread in North America. The garden variety of radish is a cultivated form of wild radish. R. sativus is white-flowered, while R. raphanistrum is yellow-flowered.

Wild Strawberry

Latin Name: Fragaria Virginiana

Native to North America, and found throughout the continent north to Alaska. Often sold as a garden ornamental, which may encourage the spread of the plant in landscaped environments.

Wild-proso Millet

Latin Name: Panicum Miliaceum

Not a native of the United States. Possibly from Asia or Europe, and now found throughout much of the western U.S.

Willowleaf Lettuce

Latin Name: Lactuca Saligna

Native to Europe, but found in nearly all states from east coast to west coast, and south into Mexico.

Witchgrass

Latin Name: Panicum Capillare

Native to the eastern United States, and now common throughout the U.S. and southern Canada.

Wool Flower

Latin Name: Lachnanthes Tinctoria

Native to eastern North America, and found from Florida to the northeast states along the Atlantic Coast.

Woolflower

Latin Name: Eriastrum Sp.

A number of different species of this genus are native plants in North America, with wide distribution in the western half of the United States, from Texas to Washington.

Woolgrass

Latin Name: Scirpus Cyperinus

Native to North America, and found throughout the eastern half of the U.S. west along the northern states to Oregon and Washington, and throughout southern Canada.

Wooly Desert Marigold

Latin Name: Baileya Pleniradiata

Native to the southwest states in the U.S. and in northern Mexico. Considered a desirable wildflower, although it may be found invading landscaped areas or growing in large plants along roadsides.

Wooly Distaff Thistle

Latin Name: Carthamus Lanatus

Native to the Mediterranean area, but now found in several states from Oregon to Texas, and sporadically along the east coast.

Wooly Plantain

Latin Name: Plantago Patagonica

Native to the western United States, and occurring in California and Oregon.

Wright Groundcherry

Latin Name: Physalis Acutifolia

Native to the southwest United States and Mexico, where it occurs now from California east along the southern states to Louisiana, and north into Missouri.

Wyeth Lupine

Latin Name: Lupinus Wyethii

Native to the western United States, and common in open fields and meadows.

Yellow Foxtail

Latin Name: Setaria Glauca

Native to Eurasia, but an important weed species in cultivated areas throughout the world, including much of the United States.

Yellow Hawkweed

Latin Name: Hieracium pratense

Native to Europe, but introduced to North America, where it now can be found throughout the northern third of the United States and southern Canada, and south in the eastern U.S. to Georgia.

Yellow Loosestrife

Latin Name: Lysimachia Vulgaris

Native to Europe, but introduced as a garden ornamental. It now occurs throughout the Northeast from Wisconsin south to Tennessee and east to the Atlantic seaboard, as well as sporadically in a few western states. Its use as a garden plant will encourage the spread to new areas.

Yellow Nutsedge

Latin Name: Cyperus Esculentus

Native to the Old World, but now spread throughout the world, including all of the United States, much of Canada, and south through the tropical areas of South America. It is one of the most important weed pests in the U.S. and much of the rest of the world.

Yellow Pond-lily

Latin Name: Nuphar Lutea

A native to North America with many varieties named. It is found throughout the United States and Canada, north to Alaska. Plants are often sold for ornamental uses, and in most situations the plants are considered of value for wildlife habitat and food. However, the rapid growth allows this species to form large, thick colonies that may create undesirable conditions for water use or water flow.

Yellow Starthistle

Latin Name: Centaurea Solstitialis

Introduced from Europe, and now one of the worst weed problems in rangeland and open areas in the western United States, particularly in California.

Yellow Sweetclover

Latin Name: Melilotus Officinalis

Native to Eurasia, but introduced as cover crops and nectar sources, and now widespread across much of the United States and into southern Canada.

Yellow Thistle

Latin Name: Cirsium Horridulum

Native to North America, and found throughout the eastern seaboard states south to Florida, and west to Texas. It also occurs in Nevada.

Yellow Toadflax

Latin Name: Linaria Vulgaris

Native to Eurasia, but introduced to the United States as an ornamental plant in the 1800's. Now found throughout North America as an aggressive invader of rangeland, where it displaces desirable grasses. Also a noxious weed along roadsides, cultivated fields, and low maintenance turf and landscape.

Yellow Woodsorrel

Latin Name: Oxalis Stricta

Native to Europe but distributed throughout the world.

Yellow-eyed Grass

Latin Name: Xyris Sp.

One of a number of species of introduced Xyris, most from South America. Found in Florida in the U.S.

Yellowspine Thistle

Latin Name: Cirsium Ochrocentrum

Native to western North America, and distributed from Texas and Nebraska to the west coast states.

Yerba Mansa

Latin Name: Anemopsis Californica

Native to the southwestern United States and northern Mexico. Widespread in California.

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