Senecio jacobaea L.

• Authority

  Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.

• Family

  Asteraceae

• Scientific Name

  Senecio jacobaea L.

• Description

  Species Description - Biennial or short-lived perennial 2–10 dm, ± fibrous- rooted to evidently taprooted, simple to the infl, thinly floccose-tomentose at first, generally glabrous or nearly so by anthesis, except often in the infl; lvs equably distributed, mostly 2–3 times pinnatifid with ± pointed segments or teeth, 4–20 × 2–6 cm, the lower petiolate and often deciduous, sometimes less dissected than the others, the upper becoming sessile; heads ± numerous in a short broad infl; disk 7–10 mm wide; invol 4 mm, its bracts ca 13, over 1 mm wide, generally dark-tipped; rays 4–8 mm; achenes minutely hairy; 2n=40, 80. Native of Europe, now established as a weed in dry soil and waste places in parts of n. U.S. and adj. Can., in our range chiefly from N.J. to se. Can. July–Oct.

• Common Names

  tansy-ragwort