Origin:
Native to southern California, and found throughout much of this state.
Biology:
An annual plant that sometimes survives as a biennial under mild winter conditions. Late germination in the summer may result in stunted plants that remain green and with flowers in the winter months. Reproduction is from seeds.
Identification:
Mature plants are very tall and upright, growing to 6 feet high from a strong taproot. Each plant is composed of a single primary stem that branches frequently near the top, and sometimes several plants will be growing close together to give the appearance of a multi-stemmed plant. The upper branches and the flower stalks bear glands that exude a sticky, fragrant substance, and the entire plant has a strong odor. Leaves are grayish-green and covered with long, silky hairs, giving the entire plant a soft look and feel. Leaves are alternate and very crowded along the lower stem, with lower leaves much larger than upper leaves. The margins of the leaves are serrated or toothed. Flower heads form singly at the ends of stalks, in crowded clusters at the top of the plant. The flower head is composed of open, bright yellow ray flowers that are slightly curled at their tips, and short yellow disc flowers. Flowering is usually in late summer. The mature seeds form a soft, dandelion-like head and each seed is equipped with the long umbrella-like pappus that aids in dispersal with the wind.
Characteristicts Important to Control:
Heavy seed production will result in large expanses of the weeds, making physical removal difficult. Plants are highly tolerant of very dry, compacted soils, and are common along roadsides and in waste areas.
