Origin:
Native to the western United States.
Biology:
A perennial plant that will grow large and shrub-like. There is a strong taproot and the crown of the plant is woody. Plants are most common on sandy, well-drained sites. Plant tissues are poisonous to livestock, containing pyrrolizidine alkaloids that cause toxicity to the liver.
Identification:
Mature plants grow almost 4 feet tall, with a primary stem that branches many times along its upper length. The leaves are thin and very long, and they are not divided, which distinguishes this species from Riddell groundsel, which has divided leaves. Leaves are smooth. Flowers occur in dense clusters at the ends of the many stems, appearing in late summer and into the fall. Flowers are yellow, and the flower head has around a half dozen long, thin yellow petals ray-like around it.
Characteristicts Important to Control:
A perennial with a strong taproot, but physical removal is easily accomplished.
