Silphium asteriscus var. dentatum
Fl. South. U.S., 221. 1860.
Plants 50–150 cm. Leaves: basal caducous; cauline opposite or alternate; faces hirsute, hispid, or scabrous. Paleae puberulent. Ray-florets 8–13. Disc-florets 35–120.2n = 14.
Phenology: Flowering summer.
Habitat: Meadows, open forests, along roadsides
Elevation: 0–1000 m
Ala., Fla., Ga., N.C., S.C., Tenn.
Varieties dentatum and angustatum are variable in the character of stem vestiture, have overlapping geographic ranges, and therefore are best treated as one variety.
"broader" is not a number.