Guayanilla

Imperata contracta (H.B.K.) Hitchc. Rep. Mo. Bot
Gard. 4 ■ 146. 1893.
Saccharum contraclum H.B.K. Nov. Gen. & Sp. 1 : 182. 1816. Saccharum dubium H.B.K. Nov. Gen. &' Sp. 1 : 183. 1816. Saccharum caudatum G. Meyer, Fl. Esseq. 68. 1818. Anatherum portoricense Spreng. Syst. 1 : 290. 1825. Anatherum caudatum Sieber ; R. & S. Syst. Veg. Slant. 2 : '445. 1824. Imperata caudata Trin. Mem.. Acad. St. Petersb. VI. 2: 331. 1832. Imperala exaltaia caudata Hack, in DC. Motiog. Phan. 6 : 99. 1889.
Stems usually 1 m. tall or more; leafsheaths smooth and glabrous, or the basal ones sometimes pubescent; blades up to 6 dm. long, 1 cm. wide or less, long-acuminate, much narrowed toward the base, hirsute on the upper surface toward the base ; panicle up to 4 dm. long, narrowed toward the apex, if,s lower branches elongated, lax and ascending ; spikelets 3-4.5 mm. long, the involucral hairs 2-3 times as long.
Type locality : On banks of the Magdalena River, Colombia.
Distribution : Mexico and Central America ; Porto Rico ; Guadeloupe ; Dominica : Martinique ; also in South America.

Perennials, Terrestrial, not aquatic, Rhizomes present, Rhizome elongate, creeping, stems distant, Stems nodes swollen or brittle, Stems erect or ascending, Stems solitary, Stems caespitose, tufted, or clustered, Stems terete, round in cross section, or polygonal, Stem internodes solid or spongy, Stems with infloresc ence less than 1 m tall, Stems with inflorescence 1-2 m tall, Stems with inflorescence 2-6 m tall, Stems, culms, or scapes exceeding basal leaves, Leaves mostly basal, below middle of stem, Leaves conspicuously 2-ranked, distichous, Leaves sheathing at base, Leaf sheath mostly open, or loose, Leaf sheath smooth, glabrous, Leaf sheath hairy at summit, throat, or collar, Leaf sheath and blade differentiated, Leaf blades linear, Leaf blade auriculate, Leaf blades 2-10 mm wide, Leaf blades 1-2 cm wide, Leaf blades mostly flat, Leaf blade with prominently raised or widened midvein, Leaf blades more or less hairy, Leaf blades scabrous, roughened, or wrinkled, Ligule present, Ligule a fringed, ciliate, or lobed membrane, Inflorescence terminal, Inflorescence a contracted panicle, narrowly paniculate, branches appressed or ascending, Inflorescence a dense slender spike-like panicle or raceme, branches contracted, Inflorescence solitary, with 1 spike, fascicle, glomerule, head, or cluster per stem or culm, Inflorescence a panicle with narrowly racemose or spicate branches, Inflorescence single raceme, fascicle or spike, Inflorescence with 2-10 branches, Peduncle or rachis scabrous or pubescent, often with long hairs, Flowers bisexual, Spikelets pedicellate, Spikelets sessile or subsessile, Spikelets dorsally compressed or terete, 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 in paired units, 1 sessile, 1 pedicellate, Spikelets bisexual, Spikelets disarticulating below the glumes, 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 3 nerved, Lemmas thin, chartaceous, hyaline, cartilaginous , or membranous, Lemma glabrous, Lemma apex acute or acuminate, Lemma awnless, Lemma margins thin, lying flat, Lemma straight, Callus or base of lemma evidently hairy, Callus hairs longer than lemma, Palea present, well developed, Palea membranous, hyaline, Palea longer than lemma, Stamens 1, Styles 2-fid, deeply 2-branched, Stigmas 2, Fruit - caryopsis.