GRASS FAMILY 67 



49. BLEPHARIDACHNE Hack. 



Low branched ])oronnials or hiciuiials. with crowded invohite leaves. Spike- 

 lets few in subcaj)itate panicles, 4-flowcred, the two lower flowers nentral, the 

 uppermost reduced to a stipitate villous 3-cleft awn. Empty glumes membranous, 

 carinate, 1-nerved, acute, glabrous, the first somewhat shorter. Lemma 3-nerved, 

 villous on the nerves, 3-lobed. with the middle lob3 longest; lobes in the neutral 

 flowers obtuse, in the perfect ones attenuate. Palet shorter, 2-keeled, 2-nerved, 

 2-toothed at the ai)ex, imperfectly develoj)ed in the neutral flowers. Stamens 2. 

 Styles 2; stigmas elongated, minutely hairy. Grain free. [Ereniochloe S. Wats., 

 not Eroiiocldon Buese.] 



1. B. Kingii (S. Wats.) Hack. Stems 3-7 cm. high, glabrous; leaf -blades 

 1-2 cm. long, rigid, revolute-setaceous, ptmgent; empty glumes 7 mm. long, 

 acuminate, purplish; lemma of the neutral flowers 4 mm. long, very villous at 

 the base; that of the perfect flower glabrous at the base, awned; rudiment 3- 

 awned. Dry barren foot-hills: Nev. — Utah — Ariz. Son. My. 



50. TRIPLASIS Beauv. Sand-grass. 



Tufted perennials. Panicles in our species narrow. Spikelet short-pedicel- 

 late, 2-6-flowered, the flowers perfect or the uppermost staminate, the rachis 

 glabrous, articulate between the flowers. Empty glumes keeled, 3-nerved, 

 shorter than the lemma. Lemma dorsally rounded at the base, 3-nerved, 

 deeply 2-lobed at the apex, with an awn arising between the lobes. Palet shorter, 

 with 2 ciliate keels, compressed. Styles short; stigmas jilumose. 



1. T. purpurea (Walt.) Chapm. Tufted perennial (?); stem 3-10 dm. 

 high, erect, prostrate or decumbent, branched below; leaf -blades 1-6 cm. long, 

 2 mm. wide, rigid, scabrous, sparsely ciliate; panicle 2-7 cm. long; spikelets 2-5- 

 flowered, 5-8 mm. long; lemma oblong, 2-lobed at the apex, with erose-truncate 

 lobes; midvein excurrent in a short point. Sandy places: Me. — Fla. — 'Tex. — • 

 N.M.— Neb. Plain. Au-S. 



51. DASYOCHLOA WiUd. 



Stoloniferous perennials. Inflorescence densely paniculate. Spikelets flat, 

 5-10-flowered ; flowers perfect. Empty glumes 2, membranous, ovate, nearly 

 equal. Lemma oblong, more or less pubescent, at least on the veins, cleft to 

 the middle, with an awn between the lobes, 3-nerved. Palet broad, prominently 

 2-keeled. Styles short, distinct; stigmas plumose. 



1. D. pulchella (H.B.K.) Willd. Densely tufted; stem 3-10 cm. high, 

 fasciculateh' branched; leaf-blades 1-3 cm. long, about 1 mm. wide, involute, 

 striate, curved, scabrous; inflorescence small and compact; spikelets 5-10- 

 flowered, 5-S mm. long; empty glumes white, lanceolate, 5-7 mm. long, acumin- 

 ate; lemma 4-6 mm. long, oblong, cleft to the middle. Triodia -pulchella H.B.K. 

 Hills and plains: Tex. — 'W Wyo. — Calif.; Mex. Son. Ap-0. 



52. ERIONEURON Nash. 



Tufted, low perennials. Panicles small, dense, subcapitate. Leaves thick, 

 with thickened white margins. Spikelets several-flowered. Empty glumes 

 narrow, acuminate. Lemma broad, 3-nerved, pubescent on the nerves below, 

 with long silky white hairs, acuminate at the apex, entire or slightly 2-toothed, 

 the terminal awn rising between the minute teeth. Style short. 



1. E. pilosum (Buckley) Nash. Stem 0..5-3 dm. high, leafy mostly at the 

 base; leaf-sheath pilose-ciliate at the summit; blades erect, thick, folded, papillose- 

 ciliate, 2-8 cm. long; spikelets 3-S, crowded, 1-1.5 cm. long; lemma 5.5-6 mm. 

 long, acuminate, entire or slightly toothed at the apex; awn 1-1.5 mm. long. 

 Tricuspis acummala Munro. Triodia acuminata Vasey. Dry gravellj' or san iy 

 soil: Kans. — -Nev. — -Ariz. — Tex. Son. — -Submont. Ap-0. 



53. TRIDENS R. & S. 



Perennials with rootstocks, ours tufted. Panicles open, or in ours narrow, 

 sometimes spike-like. Spikelets 3-many-flowered, the flowers perfect, or the 



