Origin:
Introduced from Europe and now widespread and extremely common across North America.
Biology:
A perennial weed with a deep taproot, and propagation is by the wind-blown seeds, but plants easily re-grow from the taproot if it is not removed with the upper plant. Seeds germinate in spring to early summer, or year round in irrigated landscape environments. One of the most common weeds in turf.
Identification:
Mature plants grow as a rosette of leaves around the plant crown and no true stems are present. Leaves may be as long as 12 inches and have deeply lobed margins. Older leaves will exude a milky sap if they are cut or broken. Flower stalks arise from the center of the rosette, and may grow up to 12 inches long as slender, hollow, straight stalks. Flower heads are borne singly on each stalk and are 1 to 2 inches in diameter, with bright yellow ray flowers only. The seed head that forms is a silky round ball, and attached to each seed is a stalk with long silky hairs arranged umbrella-like. These easily detach in the wind and can float for long distances.
Characteristicts Important to Control:
A perennial that re-grows from roots in the winter and from broken root segments if pulled by hand. A very deep taproot makes physical removal unlikely to succeed, and chemical applications are most effective. In addition, vast mats of dandelion can be present in turf due to the extensive seeding.