Silphium terebinthinaceum Jacq.

• 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 terebinthinaceum Jacq.

• Description

  Species Description - Taprooted; stem 0.7–3 m, essentially glabrous, nearly naked, its lvs, except those near the base, few and reduced to mere large bracts; principal lvs large, long-petiolate, the blade narrowly to broadly ovate, oblong, or elliptic, usually cordate (seldom only subtruncate) at the base, 1–5 × 0.7–3 dm, usually sharply toothed, glabrous or scabrous, sometimes hirsute on the midrib beneath; heads several or rather numerous in an open-corymbiform infl, relatively large, with ca 13 to ca 21 rays 2–3 cm, the disk 1.5–3.5 cm wide; invol 13–25 mm, its bracts essentially glabrous, strongly imbricate, the outer broadly elliptic, the inner elongate, more oblong, loose and broad- tipped; 2n=14. Prairies; s. Ont. and O. to Minn., s. to Ga. and Miss. July–Sept. (S. rumicifolium)

• Common Names

  basal-leaved rosin-wood