Silphium integrifolium Michx.

• 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

  Silphium integrifolium Michx.

• Description

  Species Description - Fibrous-rooted from a short rhizome or caudex; stems 5–15 dm; lvs firm, mostly opposite, seldom ternate or alternate, entire or toothed, ovate or lance- ovate to elliptic, mostly 7–15 × 2–6.5 cm, 2–4 times as long as wide, scabrous above, sessile and often clasping; heads relatively large and many-fld, with mostly 16–35 (commonly ca 21 or 34) rays 2–5 cm, the disk mostly 1.5–2.5 cm wide; 2n=14. Prairies and roadsides, less often in open woods; s. Mich. to Neb., s. to Ala., Miss., and Tex. July–Sept.

• Common Names

  prairie rosin-weed