Origin:
Native to the western United States, but now found across the continent to the east coast and as far north as Alaska.
Biology:
A very low-growing annual weed whose seeds may germinate in either summer or winter. If germination occurs in late summer the rosettes of leaves persist through the winter. Reproduction is by seeds.
Identification:
Mature plants are capable of growing up to 12 inches tall, as a bushy, well-branched plant. The stems are smooth and hairless and all foliage has a sweet odor when crushed, similar to the odor of pineapple. Leaves are pinnately divided one to three times, resulting in lobes that are very fine and thin and giving the plant a soft look and feel. The flower heads are very distinctive, as from one to several heads on short stalks arising from the ends of the stems. The flower head is small and conical in shape, with only the disc flowers occurring in a rounded ball, and these are yellow to greenish yellow.
Characteristicts Important to Control:
Low growing annuals that die back in the summer, but may be a problem weed in turf or landscape. Plants tolerate close mowing of turf and their thick stands may make physical removal difficult.
