Much like no. 8 [Silphium terebinthinaceum Jacq.], but with smaller and often more numerous heads, the disk 0.8-1.5 cm wide, the invol 6-11 mm, the rays 5-10, 1-2 cm; lvs often wider than long, variously merely toothed to deeply pinnatifid or palmatifid and again lobed or cleft; 2n=14. Dry, often sandy places, esp. in pine woods; Va. to Fla., w. to Tenn. and Ala. June-Sept. (S. lapsuum; S. orae; S. reniforme; S. venosum)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.