&s 



POACEAE 



25. F, reflexa Buckley. Simple or rarely tufted; stem erect, 2-5 dm. high; 

 leaf-blades flat or loosely involute, 2-10 cm. long; panicle 5-12 cm. long; spike- 

 lets 1-3- (rarely 4- or 5-) flowered, 5-7 mm. long; lemma lanceolate, smooth or 

 scabrous, 4.5*6 mm. long, attenuate; awn scabrous, 2-12, usually 5-8 mm. long. 

 Dry places: B.C. — Utah — Calif. Son, — Submont. My-Je. 



26, P, megalura Nutt. Simple or somewhat tufted; stems 2-6 dm. high, 

 glabrous; leaf -blades involute or flat; panicle 1-3 cm. long; spikelets 4-5-flowered, 

 8-11 mm. long; lemma obscurely 5-nerved, 4-6 mm. long, scabrous and ciliate 

 on its upper half; awn scabrous, 8-15 mm. long. Dry soil: B.C. — Ida. — Ariz. 

 — Calif.; Mex., Equador, Peru, and Chili. Submo7ii, Ap-Je. 



69. HESPEROCHLOA (Piper) Rydb. 



■ Dioecious perennials, densely tufted, producing both intravaginal innova- 

 tions and stout extravaginal stolons. Panicle narrow. Spikelets 3-5-flowered, 

 those of the staminate plant flattened, those of the pistillate one turgid. Empty 

 glumes 2, lanceolate, subscarious, the lower 1-nerved, the upper 3-nerved. 

 Lemma ovate, 5-nerved, acuminate. Palet shorter than the lemma. Ovary 

 hispidulous at the apex, deeply sulcate; stigma elongate, the numerous short 

 branches arising on all sides. Grain 2-dentate at the apex. 



1. H. Kingii (S. Wats.) Rydb. Stems stout, striate, glabrous, 4-10 dm. 

 high; leaf -blades firm, flat or loosely involute, coarsely striate, 1-3 cm. long, 3-6 

 mm. wide; panicle narrow, erect, 8-20 cm. long; spikelets 6-10 mm. long; empty 

 glumes nearly smooth, shining, the first 3-4.5 mm. long, the second 5-7 mm._ 

 long; lemma ovate, abruptly acuminate, scabrous, 5-8 mm. long. Poa Kingii 

 S. Wats. Fesiuca con finis Y u^ey . Canons and hillsides: Ore. — Calif. ^ — ^Colo. — 

 Neb. — Mont. Submont, — Subalp. Je-Au. 



70. BROMTJS L. Brome-guass, Chess, Cheat. 



Annuals or perennials, with paniculate inflorescence. Spikelets usually large, 

 often drooping, several-many-flowered; flowers perfect or the upper ones im- 

 perfect. Empty glumes 2, membranous, persistent, narrow, unequal, acute or 

 the second one sometimes short-awned. Lemma longer than the glumes, 

 rounded or keeled on the back, usually awned, the awn dorsal and inserted just 

 below the 2-toothed apex. Palet shorter than the lemma, 2-keeled. Ovary 

 crowTied with a villous appendage, at the base of which arise the lateral styles; 

 stigmas plumose. 



Second empty glume 5-7-nerved; first empty glume 3-nerved. 

 Lemma compressed-keeled. 



Palet less than three-fourths as long as the lemma, which is scarcely toothed. 

 Sheaths and usually also the blades hairy; lemma pubescent or hispidulous- 



scabrous. 

 Lemma hispidulous-scabrous. 



Awns 10-15 mm. long. 1. B. Hookerianus. 



AAvn 4-6 mm. long. 2. B. Flodmanii. 



Lemma pubescent; awns 4-8 mm. long. 



Lower branches of the panicle 7 cm. long or less, in fruit erect. 



Leaves flat, not canescent. 3. B. brevianstatus. 



Leaves involute, canescent. 4. B. suhrelutinus- 



Lower branches of the panicle 1 dm. long or longer, spreading in fruit. 



5. B. latior. 

 Sheaths and blades glabrous or minutely scabrous. 



Panicle narrow, strict; awn 4-6 mm- long. 6. B. polyanthus. 



Panicle open, spreading and nodding; awn 6-7 nun. long. 



5. B. paniciilatus. 



Palet more than three-fourths as long as the lemma, which is distinctly toothed 

 at the apex. 8. B. uniohides. 



Lemma rounded on the back, broadly eUiptic: introfiuced tufted annuals or biennials. 

 Lemma nearly as broad as long, awnless or with a very short a^Mi. 



9. B. brizaeformis^ 



Lemma much longer than broad, conspicuously awned. 

 Lemma and glumes glabrous. 



Awn much shorter than the lemma, nearly erect. 



Sheaths glabrous. 10. B. secalinus. 



Sheaths densely pubescent. 11. B. racemosus. 



Awn fully as long as the lemma, at maturity strongly divergent; sheaths 

 pubescent. 12. B. patulus. 



