Cylinder Jointtail Grass

Coelorachis cylindrica (Michx.) Nash
Tripsacum cylindricum Michx. Fl. Bor. Am. 1: 60. 1803.
Rottboellia campestris Nutt. Trans. Am. Phil. Soc. II. 5 : 151. 1834.
Rottboellia cylindrica Torr. Pac. R. R. Rep. 4 : 159. 1857. Not R. cylindrica Willd. 1797.
Manisuris cylindrica Kuntze, Rev. Gen. 779. 1891.
Stems from creeping rootstocks, round, 3-10 dm. tall, slender ; leaf-sheaths round, narrow ; blades 3 dm. long or less, 1-3 mm. wide ; racemes finally exserted, 1-2 dm. long,
straight or curved, the rachis barely if at all contracted at the nodes ; sessile spikelet 4.5-5 mm. long, about equaling the internode, the first scale more or less pitted in longitudinal lines, or rarely unpitted, each pit often containing a subulate hair ; pedicellate spikelet reduced to 1 or 2 short scales, the pedicel linear, shorter than the sessile spikelet and curved -around its margin.
Type locality : Florida. _ •
Distribution: In sandy soil, at low elevations, Georgia and Florida to Texas, and along the rivers to Missouri and Oklahoma.

Perennials, Terrestrial, not aquatic, Rhizomes present, Rhizome short and compact, stems close, Stems nodes swollen or brittle, Stems erect or ascending, Stems terete, round in cross section, or polygonal, Stem nodes bearded or hairy, Stem internodes solid or spongy, Stems with inflorescence 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 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 blades 2-10 mm wide, Leaf blades mostly flat, Leaf blade margins folded, involute, or conduplicate, Leaf blades mostly glabrous, Ligule present, Ligule a fringed, ciliate, or lobed membrane, Ligule a fringe of hairs, Inflorescence terminal, 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 single raceme, fascicle or spike, Flowers bisexual, Flowers unisexual, Spikelets sessile or subsessile, Spikelets dorsally compressed or terete, Spikelet less than 3 mm wide, Spikelets with 2 florets, Spikelets paired at rachis nodes, Spikelets in paired units, 1 sessile, 1 pedicellate, Pedicellate spikelet rudimentary or absent, usually sterile, Spikelets bisexual, Spikelets disarticulating below the glumes, Spikelets closely appressed or embedded in concave portions of axis, Rachilla or pedicel glabrous, Glumes present, empty bracts, Glumes 2 clearly present, Glumes equal or subequal, Glumes equal to or longer than adjacent lemma, Glumes keeled or winged, Glume with circular pits, Glumes 1 nerved, Lemmas thin, chartaceous, hyaline, cartilaginous, or membranous, Lemma 5-7 nerved, Lemma glabrous, Lemma apex acute or acuminate, Lemma awnle ss, Lemma margins thin, lying flat, Lemma straight, Palea present, well developed, Palea membranous, hyaline, Palea longer than lemma, Palea 2 nerved or 2 keeled, Stamens 3, Styles 2-fid, deeply 2-branched, Stigmas 2, Fruit - caryopsis.

Coelorachis cylindrica is a species of grass known by the common names cylinder jointtail grass, Carolina jointgrass, and pitted jointgrass. It is native to the southeastern United States.

This grass is a rhizomatous perennial with cylindrical stems growing up to 1.2 meters in height. They are clothed in the sheaths of the leaves. The inflorescence is cylindrical. The spikelets are pitted.

This grass grows on tallgrass prairies, forest edges, and sometimes roadsides.