118 NORTH AMERICAN FLORA [VorumE 17 
pressed-hirsute toward the base; racemes in pairs, rarely in 3’s or 4’s, rather stout, dark-gray, 
2.5-4 cm. long, long-exserted, the rachis of many internodes, the internodes about one half 
as long as the sessile spikelets, densely pubescent with long hairs; sessile spikelet linear- 
lanceolate, 5-6 mm. long, the first scale with the margins broadly infolded, the keels hispidulous, 
the back glabrous and slightly concave, the callus barbed with hairs about one third as long 
as the scale, the second scale with the keel hispidulous and the margins ciliate, the fourth 
scale shortly and acutely 2-toothed, ciliate, bearing an awn 7-12 mm. long, imperfect or some- 
times a little spiral at the base; pedicellate spikelet usually present, consisting of a single scale, 
the pedicel considerably shorter than the sessile spikelet. 
TYPE LOCALITY: Low pine barrens, western Florida. 
DISTRIBUTION : Western Florida. 
19. Andropogon Pringlei Scribn. & Merr. Bull. U. S. Dep. Agr. 
Agrost. 24:7. 1901. 
A tufted perennial, with erect sparingly branched stems, short leaf-blades, and lax racemes. 
Stems about 1 m. tall, glabrous; leaf-sheaths shorter than the internodes, glabrous, the upper 
ones inflated; blades narrow, those on the innovations linear, 8-12 cm. long, 1-2 mm. wide, 
usually more or less hirsute on the upper surface, those on the stem shorter and broader, 2-6 
em. long, 3-4 mm. wide, linear-lanceolate; racemes in 2’s—4’s, subdigitate, the rachis somewhat 
flexuous, the internodes and pedicels pubescent with long white hairs; sessile spikelet linear- 
lanceolate, 6-8 mm. long, about twice as long as the internodes, the first scale 2-toothed at 
the apex, hispidulous on the keels, the intercarinal space flat or nearly so, the second scale 
keeled, the fourth scale deeply 2-cleft at the apex and bearing a perfect awn 1-1.5 cm. long; 
pedicellate spikelet about 5 mm. long, reduced to 1 or 2 purplish narrow scales. 
TYPE LOCALITY: Valley of Mexico, Federal District. 
DISTRIBUTION: Known only from the type locality. 
20. Andropogon bicornis L. Sp. Pl. 1046. 1753. 
Anatherum bicorne Beauv, Agrost, 150. 1812. 
Sorgum bicorne Kuntze, Rev. Gen. 791. 1891. 
A tall usually much branched perennial, the branches repeatedly divided and borne in dense 
corymbiform masses. Stems 1 m. tall or more; leaf-sheaths glabrous; blades flat, 3-4 mm. 
broad, glabrous, or long-ciliate toward the base, those on the innovations up to 7 dm. long, 
those on the stem shorter; spathes 3-5 cm. lang, brown, somewhat distant from the racemes 
or more or less enclosing them; racemes slender, the rachis capillary, the internodes and pedi- 
cels long-hairy, the former about as long as the sessile spikelets; sessile spikelet linear-lance- 
olate, 2.5-3.5 mm. long, the first scale with the callus sparsely barbed with hairs about one 
half as long as the scale, the fourth scale entire, acute, awnless; pedicellate spikelet usually 
reduced to a single scale, or rarely larger and staminate. 
TYPE LOCALITY: Jamaica. 
DISTRIBUTION : Throughout tropical America. 
ILLUSTRATION: Beauv. Agrost. p/. 22, f. 11, 
21. Andropogon leucostachyus H.B.K. Nov. Gen. & 
Sp. 1: 187. 1816. 
Andropogon virginicus I. Sp. Pl. ed. 2. 1482, in part. 1763. Not A. virginicus L. 1753. 
Anatherum virginicum Spreng. Pugill. 2: 16, in part. 1815, 
Andropogon lanuginosus H.B.K. Nov. Gen. & Sp. 1: 187. 1816. 
Anatherum domingense R. & S. Syst. Veg. 2: 809. 1817. 
Andropogon domingensis Fourn. Mex. Pl. Gram, 61. 1881. 
Sorgum leucostachyum Kuntze, Rev. Gen. 792, 1891. 
A densely tufted perennial. Stems 3-8 dm. tall, slender, or sometimes stout, branched 
above, the branches elongate, slender, glabrous; ligules 1-1.5 mm. long, truncate or rounded; 
leaf-sheaths glabrous; blades up to 3 dm. long, 1.5-2, or rarely 5 mm. wide, glabrous; racemes 
in 2’s~5’s, 3-6 cm. long, the internodes of the rachis capillary; sessile spikelet 2.5-4 mm. long, 
the first scale membranous, the callus barbed with hairs about one half the length of the scale, 
