Parthenium integrifolium 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

  Parthenium integrifolium L.

• Description

  Species Description - Perennial 3–10 dm from a tuberous-thickened, usually short root; stem simple or branched above, strigose-puberulent above, often glabrous below; lvs large and sometimes few, crenate-serrate, or sublyrate at base, scabrous to subglabrous, the basal long- petiolate, with lance-elliptic to broadly ovate blade 7–20 × 4–10 cm, the cauline progressively shorter- petiolate and generally reduced, the upper often sessile and clasping, but less conspicuously so than in the next 2 spp.; heads numerous in a flat-topped infl, the disk 4–7 mm wide; rays scarcely 2 mm; achenes obovate, black, 3 mm; 2n=72. Prairies and dry woods; Va. to se. Minn., s. to Ga. and Ark., and adventive in Mass. June–Sept.

• Common Names

  eastern parthenium