Silphium mohrii Small

Fibrous-rooted from a short rhizome or crown, 6–15 dm, copiously shaggy-hispid, many or most of the hairs of the stem over 2 (to 5) mm; lvs alternate, opposite, or in part ternate, entire or toothed, the basal and lower cauline ones well developed and persistent, with broadly ovate to merely lanceolate, basally rounded or abruptly contracted blade 12–30 × 3–20 cm on a petiole 5–20 cm; cauline lvs progressively reduced upwards, becoming sessile, often ovate; heads several or rather numerous, with ca 13 rays 1.5–2 cm, the disk 1.5–2.5 cm wide. Glades and open woods; Cumberland Plateau region of Ky., Tenn., Ala., and Ga. July–Oct. The Ky. plants, with broad, basally truncate-cordate lower lvs, glabrous invol, and not quite so long and shaggy pubescence on the stem (hairs 2–3 mm), have been described as S. wasiotensis Medley and may be distinct.