Tweedy's Reedgrass

Calamagrostis tweedyi (Scribn.) Scribn.; Vasey, Contr U. S. Nat. Herb. 3: 83. 1892.
Deyeuxia Tweedyi Scribn. Bull. Torrey Club 10: 64. 1883.
Culms erect, rather stout, about 3-noded, glabrous, 1-1.5 m. tall, with short rhizomes; sheaths glabrous or roughish toward the summit, the lower becoming fibrous; ligule thin, 4-7 mm. long; blades flat, somewhat scabrous, the cauline 5-15 cm. long, as much as 1 cm. wide, those of the innovations narrower and longer; panicle oblong, erect, purplish, more or less spikelike, often interrupted below, about 10 cm. long, the axis glabrous, the branches short and crowded, scaberulous; glumes abruptly acuminate, glabrous, 6-7 mm. long; lemma scaberulous, about as long as the glumes, the awn from below the middle, twisted, geniculate, exserted about 5 mm., the callus-hairs scant, scarcely 1 mm. long; rachilla pilose, 2 mm. long.
Type locality: Cascade Mountains, Washington {Tweedy). Distribution: Known only from the Cascade Mountains, Washington.