This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol1", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Tall generally robust perennial grasses, with long flat leaves, and perfect flowers in terminal panicles. Spikelets generally with a ring of hairs at the base, 2 at each node of the jointed rachis, one sessile, the other with a pedicel, generally 1-flowered. Scales 4, the two outer indurated, the inner hyaline, the fourth bearing a terminal straight or contorted awn; palet small, hyaline; stamens 3. Grain oblong, free, enclosed in the scales. [Greek, referring to the woolly spikelets.]
About 21 species, natives of the temperate and tropical regions of both hemispheres. Besides the following, three or four others occur in the Southern States. Type species: Anthoxanthum gigantcum Walt.
Awns flat, closely spiral at the base, geniculate; apex of the fourth scale deeply 2-cleft.
Basal hairs twice as long as the yellowish spikelets which are nearly concealed in the copious
hairs of the cream-colored panicle.
Basal hairs sometimes equaling but not exceeding the brown spikelets which are plainly
visible through the brown panicle.
Awn terete, or flat only at the very base, not spiral at the base, straight; fourth scale usually
entire, rarely shortly 2-toothed.
Spikelets 2"-3" long, exceeded by the basal hairs.
Spikelets 4"-4 1/2" long, much exceeding the basal hairs.
Andropogon divaricatus L. Sp. PI. 1045. 1753. Andropogon alopecuroides L. Sp. PI. 1045. 1753. Erianthus alopecuroides Ell. Bot. S. C. & Ga. 1: 38.
1816. Erianthus divaricatus Hitchc. Contr. U. S. Nat. Herb.
12: 125. 1908.
Culms stout, erect, 6°-10° tall; nodes naked or barbed, the summit and the axis of the panicle densely pubescent with appressed long rigid silky hairs. Sheaths glabrous or hirsute; blades usually glabrous, 6'-2° long, 1/2'-1' wide, acuminate, narrowed and sometimes hairy on the upper surface near the base; panicle oblong, 7'-12' long, 2'-3' wide, branches 3'-5' long, slender, loose; outer scales of the spike-let about 3" long, exceeding the pedicel and about two-thirds as long as the basal hairs, lanceolate, acuminate; inner scales shorter, the awn 6"-8" long, scabrous.