Diectomis fastigiata (Sw.) P. Beauv.

Diectomis fastigiata (Sw.) Beauv. Agrost. 150, 160. 1812
Andropogon fastigiatus Svj . Prodr. 26. 1788. Pa Uinta fastigiata Spreng. Pugill. 2 : 13. 1815. Andropogon Hochstetteri Steud. Syn. Gram. 384. 1854. Heteropogon Hochstetteri Schweini. Beitr. Fl. Aeth. 310. 1867. Sorgum fas iigia turn Kuntze, Rev. Gen. 791. 1891.
Stems up to 1 m. tall, branched, the branches in l's-3's; leaf-sheaths loose, keeled; ligules 5-10 mm. long, broader than the leaf-blades; blades of the innovations up to 3 dm. long, 1-4 mm. wide, glabrous, or sparsely ciliate at the base, rough on both surfaces; spike-like racemes 4-8 cm. long, the intemodes shorter than the sessile spikelets, ciliate on the margins with white spreading hairs; sessile spikelet 4-5 mm. long, the first scale with an obtuse callus nearly 1 mm. long, 2-nerved in addition to the hispidulous keels, the center of the upper part pilose with long hairs, the second scale obovate-cuneate, the keel long-ciliate, the awn 3-4 times as long as the scale, the fourth scale about one half as long as the second, ciliolate, elliptic, the awn 3.5-4.5 mm. long, glabrous, the dark-brown straight or indistinctly geniculate column about one half as long as the yellow subula ; pedicellate spikelet with the first scale herbaceous, curved-obovate, flat, 15-nerved or more, bearing a straight awn as long as itself, the second scale half as long as the first, membranous, bearing a short awn, the fourth scale long-ciliate, muticous.
Type locality : Jamaica.
Distribution ; Tropics.

Annuals, Terrestrial, not aquatic, Stems nodes swollen or brittle, Stems erect or ascending, Stems geniculate, decumbent, or lax, sometimes rooting at nodes, Stems caespitose, tufted, or clustered, Stems terete, round in cross section, or polygonal, Stem internodes hollow, Stems with inflorescence less than 1 m tall, Stems with inflorescence 1-2 m tall, Stems, culms, or scapes exceeding basal leaves, Leaves mos tly cauline, Leaves conspicuously 2-ranked, distichous, Leaves sheathing at base, Leaf sheath mostly open, or loose, Leaf sheath smooth, glabrous, Leaf sheath and blade differentiated, Leaf blades linear, Leaf blade auriculate, Leaf blades very narrow or filiform, less than 2 mm wide, Leaf blades 2-10 mm wide, Leaf blades mostly flat, Leaf blades mostly glabrous, Ligule present, Ligule an unfringed eciliate membrane, Inflorescence terminal, Inflorescence with 2 or more spikes, fascicles, glomerules, heads, or clusters per culm, Inflorescence a panicle with narrowly racemose or spicate branches, Flowers bisexual, Spikelets pedicellate, Spikelets sessile or subsessile, Spikelets laterally compressed, Inflorescence or spikelets partially hidden in leaf sheaths, subtended by spatheole, Spikelet less than 3 mm wide, Spikelets with 1 fertile floret, Spikelets with 2 florets, Spikelet with 1 fertile floret and 1-2 sterile florets, Spikelets paired at rachis nodes, Spikelets bisexu al, Spikelets falling with parts of disarticulating rachis or pedicel, Spikelets conspicuously hairy , Rachilla or pedicel hairy, Glumes present, empty bracts, Glumes 2 clearly present, Glumes distinctly unequal, Glumes equal to or longer than adjacent lemma, Glume equal to or longer than spikelet, Glumes awned, awn 1-5 mm or longer, Glumes keeled or winged, Glumes 1 nerved, Lemma glabrous, Lemma apex dentate, 2-fid, Lemma distinctly awned, more than 2-3 mm, Lemma with 1 awn, Lemma awn 2-4 cm long or longer, Lemma awn from sinus of bifid apex, Lemma awn twisted, spirally coiled at base, like a corkscrew, Lemma awn once geniculate, bent once, Lemma margins thin, lying flat, Lemma straight, Palea present, well developed, Palea membranous, hyaline, Palea shorter than lemma, Stamens 3, Styles 2-fid, deeply 2-branched, Stigmas 2, Fruit - caryopsis, Caryopsis ellipsoid, longitudinally grooved, hilum long-linear.

Andropogon fastigiatus là một loài thực vật có hoa trong họ Hòa thảo. Loài này được Sw. mô tả khoa học đầu tiên năm 1788.