MANUAL OF THE GRASSES OF THE UNITED STATES 



433 



1. Crypsis niliaca Fig. and De 



Not. (Fig. 621.) Freely branching, 

 prostrate, the mats to 30 cm. in diam- 

 eter, often depauperate, 2 to 3 cm. 

 wide; sheaths tuberculate, the sum- 

 mit bearded; blades flat, involute 

 toward the apex, 2 to 5 cm. long, 

 spreading, readily falling from the 

 sheaths, mature plants mostly blade- 

 less; glumes about 3 mm. long, mi- 

 nutely pilose; lemma and palea about 

 as long as the glumes, the broad palea 

 readily splitting between the nerves. 

 (Described under C. aculeata in Man- 

 ual, ed. 1.) O — Overflowed land, 

 dried mud flats, sand bars, and wet 

 alkali ground, Sacramento and San 

 Joaquin Valleys and in Humboldt, 

 Santa Clara, and Los Angeles Coun- 

 ties, Calif. Introduced; first found at 

 Norman, Glenn County, and in alkali 

 hollow, Colusa County, in May 1898, 

 the source of the seed not known. The 

 grass is slowly spreading, the latest 

 collection being made in Santa Clara 

 County in 1942. Egypt and south- 

 western Asia. 



86. HELEOCHLOA Host ex Roemer 



Spikelets 1-flowered, the rachilla 

 mostly disarticulating above the 

 glumes; glumes about equal, narrow, 

 acute; lemma broader, thin, 1-nerved, 

 a little longer than the glumes; palea 

 nearly as long as the lemma, readily 

 splitting between the nerves. Low 

 spreading tufted annuals with oblong, 

 dense, spikelike panicles, the subtend- 

 ing leaves with inflated sheaths and 

 reduced blades. Type species, Heleo- 

 chloa alopecuroides. Name from Greek 

 helos, marsh, and chloa grass, allud- 

 ing to the habitat of the type species. 



1. Heleochloa schoenoides (L.) 

 Host. (Fig. 622, A.) Culms tufted, 

 branching, erect to spreading and 

 geniculate, 10 to 30 cm. long; sheaths 

 often somewhat inflated; blades flat, 

 with involute slender tips, mostly less 

 than 10 cm. long, 2 to 4 mm. wide; 

 panicle pale, 1 to 4 cm. long, 8 to 

 10 mm. thick; spikelets about 3 mm. 



long; pericarp readily separating. O 

 — Waste places, Massachusetts to 

 Wisconsin, south to Delaware, Ohio, 

 Illinois, and Iowa; California; intro- 

 duced from Europe. 



Heleochloa alopecuroides (Pill, and 

 Mitterp.) Host. (Fig. 622, B.) Differ- 

 ing from H. schoenoides in the more 

 slender panicles, 4 to 5 mm. thick, ex- 

 serted at maturity; spikelets about 2 

 mm. long. O — Ballast, Philadel- 

 phia, Pa., and near Portland, Oreg.; 

 Europe. 



87. BRACHYELYTRUM Beauv. 



Spikelets 1-flowered, the rachilla 

 disarticulating above the glumes, 

 prolonged behind the palea as a 

 slender naked bristle ; glumes minute, 

 the first often obsolete, the second 

 sometimes awned; lemma firm, nar- 

 row, 5-nerved, the base extending 

 into a pronounced oblique callus, the 

 apex terminating in a long straight 

 scabrous awn. Erect, slender peren- 

 nials with short slender knotty rhi- 

 zomes, flat blades, and narrow, rather 

 few-flowered panicles. Type species, 

 Brachyelytrum erectum. Name from 

 Greek brachus, short, and elutron, 

 cover or husk, alluding to the short 

 glumes. 



1. Brachyelytrum erectum 

 (Schreb.) Beauv. (Fig. 623.) Culms 

 60 to 100 cm. tall; sheaths sparsely 

 retrorse-hispid, rarely glabrous; blades 

 mostly 7 to 15 cm. long, 1 to 1.5 

 cm. wide, scabrous, sparingly pilose 

 beneath, at least on the nerves and 

 margin; panicle 5 to 15 cm. long, the 

 short branches appressed; second 

 glume 0.5 to 2 mm. long; lemma 

 subterete, about 1 cm. long, sca- 

 brous, the nerves sometimes hispid, 

 the awn 1 to 3 cm. long. % — 

 Moist or rocky woods, Newfoundland 

 to Minnesota, south to Georgia, 

 Louisiana, and Oklahoma. Plants 

 with lemmas scabrous only toward 

 the summit and on the nerves have 

 been named B. erectum var. septen- 

 trionale Babel. 



