Tansy Ragwort

Senecio jacobeae

Family: Asteraceae

Description and Life Cycle

A biennial to short-lived perennial, spreading by prolific seed production (in excess of 150, 000 seeds per plant). A low-growing rosette of leaves is produced in the first year. Erect stems, 0.3-1.2 m high, are produced in the second and subsequent years. The dark green, stalk-less leaves are deeply lobed into irregular segments, giving the plant a "ragged" appearance. The daisy-like, bright yellow flowers are in bloom from July through September. Tansy ragwort is poisonous to livestock; cattle and horses are most seriously affected, sheep seldom.

Biological Control Agents

• Cochylis atricapitana - Moth
• Botanophila seneciella - Fly
• Longitarsus flavicornis - Beetle
• Longitarsus jacobaeae - Beetle
• Tyria jacobaeae - Moth

References

Cranston, R., D. Ralph and B. Wikeem. 2005. Field guide to noxious and other selected weeds of British Columbia. Gov. of BC. 94 p.

Powell, G. W., A. Sturko, B. Wikeem and P. Harris. 1994. Field guide to the biological control of weeds in British Columbia. B.C. Min. For. Res. Prog.