Paspalum virgatum L.

Perennials; rhizome short, culm tufted, erect, 1-2 m high. Blade stiff, margins sharp with siliceous bodies; sheath keeled, compressed, lower ones softer, papery. Inflorescence of racemose racemes, numerous; rachis prominently covered with papillate bristles. Spikelets obovate, 2.2-2.5 mm long, densely 4-rowed, brownish, margins hairy, prominent at summit; lower glume reduced; upper glume 3- veined, convexed on dorsal part, subequal to spikelet, margins and summit soft hairy; lower lemma and upper glume subequal, with marginal hairs, flat on dorsal part, upper floret brownish, coriaceous, slightly shorter than spikelet.

Perennial from short rootstock. Culms robust, forming a dense tussock, erect, 1–2 m tall. Leaf sheaths compressed, usually papillose-hirsute at margins and summit; leaf blades linear, flat, stiff, 30–75 × 1–2.5 cm, margins serrate, apex acuminate; ligule 2–3 mm. Inflorescence axis 10–30 cm; racemes up to 20, 5–15 cm, ascending or drooping; spikelets paired, in 4 dense rows; rachis 0.5–1.5 mm wide, scabrous, glabrous or with a few setae. Spikelet brownish, obovate, 2.2–3 mm, acute; upper glume membranous, 3–5-veined, dorsally puberulous, margins fringed with short silky hairs above middle; lowerlemma resembling upper glume but glabrous; upper lemma brownish, as long as spikelet, coriaceous, finely punctulate-striate, subacute. Fl. and fr. summer–autumn. 2n = 40, 80.

Originally from Jamaica, now naturalized elsewhere. Taiwan, naturalized in the northern part.

Moist or swampy ground, naturalized. N Taiwan [native to America from the United States to Brazil].

Paspalum virgatum L. Syst. Nat. ed. 10. 855. 1759
? Paspalum laiifolium Spreng. Syst. 1 : 248. 1825.
y Paspalum plaiyphyllum Schultes, in R. & S. Syst. Veg. Mant. 3 : 557. 1827.
Paspalum leucocheilum Wright ; Sauv. Anal. Acad. Ci. Habana 8 : 203. 1871.
Stems up to 1 m. tall or more, simple, stout, glabrous; leaf -sheaths glabrous, the lower ones prominently reticulate; blades up to 5 dm. long and 3 cm. wide, linear, smooth and glabrous; racemes 10 or more, erect or ascending, up to 1.5 dm. long, the rachis 1.25-1.5 mm. wide, commonly setiferous; spikelets 2.3-2.5 mm. long, 1.6-2 mm. wide, elliptic, broadly obovate to nearly orbicular, the first scale wanting, the second and third scales ciliate toward the apex, glabrous on the siuface or sometimes appressed-pubescent, the second scale 5-nerved, the third 3-nerved, the fruiting scale becoming brown at maturity, prominently marked with papillae in longitudinal rows.
Type locality : Jamaica.
Distribution : Southern Mexico to Costa Rica ; Jamaica and Cuba to Grenada ; also in tropical South 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 internodes solid or spongy, 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 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 2-10 mm wide, Leaf blades 1-2 cm wide, Leaf blades 2 or more cm wide, Leaf blades mostly flat, Leaf blades mostly glabrous, Leaf blades scabrous, roughened, or wrinkled, Ligule present, Ligule an unfringed eciliate membrane, Inflorescence terminal, Inflorescence solitary, with 1 spike, fascicle, glomerule, head, or cluster per stem or culm, Inflorescence a panicle with narrowly racemose or spicate branches, Inflorescence branches more than 10 to numerous, Inflorescence branches 1-sided, Rachis dilated, flat, central axis to which spikelets are attached, Rachis winged, Rachis angular, Flowers bisexual, Spikelets pedicellate, 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 all alike and fertille, Spikelets bisexual, Spikelets disarticulating below the glumes, Spikelets conspicuously hairy , Spikelets secund, in rows on one side of rachis, Rachilla or pedicel glabrous, Glumes present, empty bracts, Glumes 1 clearly present, the other greatly reduced or absent, Glumes distinctly unequal, Glumes equal to or longer than adjacent lemma, Glume equal to or longer than spikelet, Glumes 3 nerved, Lemma similar in texture to glumes, Lemma 3 nerved, Lemma glabrous, Lemma apex truncate, rounded, or obtuse, Lemma awnless, Lemma straight, Palea present, well developed, Palea shorter than lemma, Stamens 3, Styles 2-fid, deeply 2-branched, Stigmas 2, Fruit - caryopsis.