Trachypogon spicatus (L. fil.) Kuntze

spicatus: arranged in a spike; spicate

Trachypogon canescens Nees, Agrost. Bras. 343. 1829
Andropogon canescens Kunth, I^num. 1 : 487. 1833.
Whole plant silkyvillous. Stems up to 1 m. tall, sometimes glabrous ; leaf-blades terete, channeled on the upper surface, up to 5 dm. long, about 1 mm. in diameter ; ligule 2-4 mm. long; raceme single, terminating the stem, the pilose or 'glabrous axis 1-1.5 dm. long ; staminate spikelet linear-oblong, about 7 mm. long, the first scale pilose with long hairs, the fourth scale sometimes bearing a short exserted straight awn ; perfect spikelet with a barbed callus about 3 mm. long, the first scale silky-villous, about 8 mm. long, the awn of the fourth scale 3^5 cm. long, the column and sometimes the base of the subula hirsute with long ascending hairs, the remainder of the awn hispidulous.
Type locality: Southern Brazil.
Distribution : Mexico and (according to Fournier) Nicaragua ; also in Brazil.

Trachypogon karwinskyi (Hack.) Nash, sp. nov
Trachypogon polymorphus Karwinskyi Hack, in DC. Monog. Phan. 6 : 329. 1889.
Leaves unknown ; racemes in 3's, terminating the stem, the puberulent axis 10-12 cm. long ; staminate spikelets 6 mm. long, linear-oblong, very densely appressed-pilose ; per-
i
feet spikelets 9 mm. long, linear-oblong, densely appressed-pilose, the awn of the fourth scale 2-2.5 cm. long, the column shortly appressed-hirtulous, the hairs shorter than the diameter of the column, the subula about equaling the column in length.
Type locality : Mexico-.
Distribution : Known only from the type locality.

Trachypogon palmeri Nash, sp. nov
Stems up to 13 dm. long, barbed at the nodes, otherwise smooth and glabrous ; leafsheaths glabrous ; ligule, that of the lower leaves, 1-2 cm. long ; blades up to 3 dm. long, 1-2 mm. wide, rough, involute ; raceme single, terminating the stem, the glabrous axis 6-10 cm. long ; staminate spikelet on a short pedicel, 6-8 mm. long, oblong-linear, the first scale rather sparingly pubescent or glabrescent ; perfect spikelet with a long-hairy callus
w
about 2 mm. long, the first scale about 8 mm. long, hirsute with ascending hairs, the awn of the fourth scale 7-8 cm. long, the spiral column appressed-hirsute, a little longer than the subula, which is hispidulous and somewhat contorted.
Type collected at Guadalajara, state of Jalisco, Mexico, July-Oct., 1886, Edward Palmer 467 . Distribution : Known only from the type locality.

Trachypogon plumosus (H. & B.) Nees, Agrost. Bras. 344. 1829
Andropogon plumosus H. & B.; Willd. Sp. PI. 4: 918. 1806.
Trachypogon mollis Nees, Agrost. Bras. 343. 1829.
Heteropogon stipoides Presl, Reliq. Haenk. 1 : 335. 1830.
Heteropogon secundus Presl, Reliq. Haenk. 1 ; 335. 1830.
Andropogon stipoides Kunth, Enum. 1 : 487. 1833.
Trachypogon dissolutus Nees, Linnaea 19 : 695, 1847.
Andropogon dactyloides Steud. Syn, Gram. 381. 1855.
Trachypogon violaceus Anderss. Oefv. Sv. Vet.-Akad. Forh. 1857 : 49. 1857.
Trachypogon Preslii Anderss. Oefv. Sv. Vet.-Akad. Forh. 1857 : 50. 1857.
Trachypogon dactyloides Fourn. Mex. PI. Gram. 66. 1881.
Trachypogon Mulleri Fourn. Mex. PI. Gram. 66. 1881.
Trachypogon secundus Arechav. Anal. Mils. Nac. Montevideo 3 : 270. 1895.
Stems up to 1.5 m. tall, barbed at the nodes, otherwise glabrous ; leaf -sheaths glabrous, or sometimes pubescent ; ligule up to 3 cm. long ; blades fiat, or sometimes involute, up to 4.5 dm. long, 3-8 mm. wide, smooth or rough, glabrous or pubescent ; racemes single, or in 2's or 3's, terminating the stem, the glabrous axis up to 2 dm. long; staminate spikelets 6-8 or rarely 10 mm. long, the first scale hirsute, oblong to linear or obovate-oblong ; perfect spikelets with a long-hairy callus 1.5-2 mm. long, the first scale hirsute, 6-8 mm. long, the awn of the fourth scale 4.5-8 cm. long, the spiral column a little longer than the hispid or hispidulous subula, shaggy with long hairs.
Type locality : Cumana, Venezuela.
Distribution : Texas to Arizona, and continental tropical America.

Perennials, Terrestrial, not aquatic, Stems nodes swollen or brittle, Stems erect or ascending, Stems caespitose, tufted, or clustered, Stems terete, round in cross section, or polygonal, Stem nodes bearded or hairy, Stem internodes hollow, Stems with inflorescence less than 1 m tall, Stems with inflorescence 1-2 m tall, Stems, culms, or scapes exceedin g basal leaves, Leaves mostly basal, below middle of stem, Leaves mostly cauline, Leaves conspicuously 2-ranked, distichous, Leaves sheathing at base, Leaf sheath mostly open, or loose, Leaf sheath hairy, hispid or prickly, Leaf sheath and blade differentiated, Leaf blades linear, Leaf blades very narrow or filiform, less than 2 mm wide, Leaf blades 2-10 mm wide, Leaf blades mostly flat, Leaf blade margins folded, involute, or conduplicate, Leaf blade with prominently raised or widened midvein, Leaf blades mostly glabrous, Ligule present, Ligule an unfringed eciliate membrane, Inflorescence terminal, Inflorescence racemose, Inflorescence simple spikes, Inflorescence solitary, with 1 spike, fascicle, glomerule, head, or cluster per stem or culm, Inflorescence with 2 or more spikes, fascicles, glomerules, heads, or clusters per culm, Inflorescence single raceme, fascicle or spike, Inflorescence branches paired or digitate at a single node, Inflorescence branches paired racem es, V-shaped, Flowers bisexual, Flowers unisexual, Spikelets pedicellate, Spikelets dorsally compressed or terete, Spikelet less than 3 mm wide, Spikelets with 1 fertile floret, Spikelets with 2 florets, Spikelet with one perfect floret and one staminate floret, Spikelet with 1 fertile floret and 1-2 sterile florets, Spikelets paired at rachis nodes, Spikelets in paired units, 1 sessile, 1 pedicellate, Spikelets bisexual, Spikelets unisexual, Spikelets disarticulating below the glumes, Spikelets falling with parts of disarticulating rachis or pedicel, Spikelets conspicuously hairy , Rachilla or pedicel glabrous, Glumes present, empty bracts, Glumes 2 clearly present, Glumes equal or subequal, Glumes equal to or longer than adjacent lemma, Glume equal to or longer than spikelet, Glume surface hairy, villous or pilose, Glumes 1 nerved, Lemmas thin, chartaceous, hyaline, cartilaginous, or membranous, Lemma 3 nerved, Lemma body or surface hairy, Lemma apex acute or acuminate, Le mma distinctly awned, more than 2-3 mm, Lemma with 1 awn, Lemma awn 2-4 cm long or longer, Lemma awned from tip, Lemma awn twisted, spirally coiled at base, like a corkscrew, Lemma awn once geniculate, bent once, Lemma awn twice geniculate, bent twice, Lemma margins thin, lying flat, Lemma straight, Callus or base of lemma evidently hairy, Callus hairs shorter than lemma, Stamens 3, Styles 2-fid, deeply 2-branched, Stigmas 2, Fruit - caryopsis, Caryopsis ellipsoid, longitudinally grooved, hilum long-linear.

Trachypogon spicatus là một loài thực vật có hoa trong họ Hòa thảo. Loài này được (L.f.) Kuntze miêu tả khoa học đầu tiên năm 1891.