Catalina Grass

Dissanthelium californicum (Nutt.) Benth. in Hook. Ic 14:56. 1881.
Slenochloa californica Nutt. Jour. Acad. Phila. II. 1: 189. 1848.
Aimual, lax; culms more or less decumbent or spreading, glabrous, about 30 cm. tall; sheaths glabrous, rather loose, striate-nerved; ligule truncate, 3 mm. long; blades flat, lax, glabrous, 10-15 cm. long, 1-3 mm. wide, the uppermost near the panicle, not reduced; panicle narrow, loose, about 15 cm. long, the axis glabrous, the branches fascicled, ascending, flexuous, some of them floriferous from the base; spikelets 2-flowered (rarely 3-flowered), the rachilla between the florets slender, glabrous, 0.5 mm. long; glumes longer than the two florets, narrow, acute, glabrous, nearly equal, about 3 mm. long, the first 1-nerved, the second 3-nerved; lemmas pubescent, ovate-lanceolate, compressed, nearly 2 mm. long.
Typb locality: Santa Catalina Island, California (Gambel).
Distribution: Open ground, islands off the coast of southern California and Baja California.

Annuals, Terrestrial, not aquatic, Stems nodes swollen or brittle, 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, culms, or scapes exceeding basal leaves, Leaves mostly cauline, Leaves conspicuously 2-ranked, distichous, Leaf tips flexuous, drooping, blades thin, lax, soft, 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 blades mostly glabrous, Lig ule present, Ligule an unfringed eciliate membrane, Inflorescence terminal, Inflorescence a contracted panicle, narrowly paniculate, branches appressed or ascending, Inflorescence solitary, with 1 spike, fascicle, glomerule, head, or cluster per stem or culm, Inflorescence with 2-10 branches, Inflorescence branches more than 10 to numerous, Flowers bisexual, Spikelets pedicellate, Spikelets laterally compressed, Spikelet less than 3 mm wide, Spikelets with 2 florets, Spikelets with 3-7 florets, Spikelets solitary at rachis nodes, Spikelets all alike and fertille, Spikelets bisexual, Spikelets disarticulating beneath or between the florets, Spikelets secund, in rows on one side of rachis, 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, Glumes keeled or winged, Glumes 3 nerved, Lemmas thin, chartaceous, hyaline, cartilaginous, or membranous, Lemma similar in texture to glumes, Lemma 3 nerved, Lemma glabrous, Lemma body or surface hairy, Lemma apex acute or acuminate, Lemma awnless, Lemma margins thin, lying flat, Lemma straight, Lemma surface pilose, setose or bristly, 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.

Dissanthelium californicum (California dissanthelium, Catalina grass) is a rare species of grass in the family Poaceae. It was originally discovered on Santa Catalina, an island off California's coast in 1847 by U.S. botanist and naturalist William Gambel. It was later identified as growing on Guadalupe Island (off Baja California Peninsula), on San Clemente Island and Catalina Island (both off southern California).

Last seen in 1912, Dissanthelium californicum was generally thought to be extinct, until examples were found on March 29, 2005, by Jenny McCune of the Catalina Island Conservancy on Catalina Island.[1] In 2010, two populations were found on San Clemente Island. It has not reappeared on Guadalupe Island.