Origin:
Introduced from South America, and now distributed along the west coast from Washington to California.
Biology:
An annual plant occurring in most non-crop settings, particularly along roadsides and dry, disturbed areas. Propagation is from seeds, and plants mature and flower in the late summer into fall, with dead stalks and flower heads remaining into the winter.
Identification:
Mature plants are very tall and spindly looking, growing to over 5 feet tall. Early growth, however, is one or more densely foliated stalks, and as the plant matures it puts up long, thin stems that terminate in multiple short branches and flower heads at their ends. Stems often have long, pointed leaves alternating along their length, or they may be leafless. The entire plant is covered with glandular hairs that exude a sticky sap that is very strong-scented, and gathers dust onto it giving the plants a dirty appearance. Flower heads are small and in sparse clusters, but open to showy yellow or yellow and red colors. Flowers are usually at the ends of the stems, but also may occur in the leaf axils.
Characteristicts Important to Control:
An annual weed easily removed by hand pulling. Dry places are preferred.