64 GRAMINEAE (GRASS FAMILY) 



long: glumes very unequal, 3-lobed and 3-awned, pubescent on the back be- 

 low. Colorado to Mexico. 



39. ATHEROPOGON Muhl. 



Slender perennials with narrow leaves and numerous short straight scattered 

 often reflexed spikes arranged in a long one-sided raceme. Spikelets 1- 

 flowered; the rachilla surpassing the flower and bearing awns or scales at its 

 summit. Glumes unequal, narrow, keeled; lemma broader, 3-toothed and 

 awned, inclosing the 2-toothed palet. Stamens 3. Styles distinct, with 

 plumose stigmas. Grain free, inclosed in the lemma. Bouteloua in part. 



1. Atheropogon curtipendula (Michx.) Fourn. Mex. PI. En. Gram. 138. 1881. 

 Stems tufted, 3-6 dm. high, simple, smooth: leaves narrow, flat or involute, 

 rough at least above: spikes about 1 cm. long, nearly sessile, 20-60 in num- 

 ber, in a loose one-sided general spike or raceme: glumes scabrous on the 

 keel: anthers orange-red. Bouteloua racemosa. Dry soil, hillsides and fields; 

 very widely distributed in North America. 



40. BECKMANNIA Host. 



An erect perennial grass with flat leaves and a long terminal narrow panicle. 

 Spikelets subsessile, broad, compressed, 1-2-flowered. Empty glumes mem- 

 branous, compressed, concave-inflated, obtuse or abruptly acute, 1-2-flowered; 

 lemma narrow, membranous; palet hyaline, 2-keeled. Stamens 3. Styles dis- 

 tinct, with plumose stigmas. Oblong grain free but inclosed in the lemma and 

 palet. 



1. Beckmannia erucaeformis (L.) Host. Gram. Austr. 3: 5. 1805. Stems 

 stout, 3-10 dm. high: leaves 1-3 dm. long; ligules elongated: panicle 1-3 dm. 

 long, erect, strict, secund, the short crowded branchlets densely flowered from 

 the base: spikelets nearly orbicular, the upper rudimentary floret minute, 

 stipitate. In wet swales; widely distributed west of the Mississippi. 



41. BUCHLOE Engelm. BUFFALO GRASS 



Perennial, creeping or stoloniferous. Spikelets dioecious (rarely monoe- 

 cious), very unlike: staminate spikelet 2-3-flowered, sessile in two rows in 

 short one-sided spikes; glumes 1-nerved, subacute, the second larger but 

 shorter than the florets; lemma 3-nerved, slightly exceeding the palet: pistil- 

 late spikelets 1 -flowered, in short spikes; glumes nearly equal, united at the 

 base, 3-toothed, indurated, larger than the floret; lemma narrow, mem- 

 branaceous, 2-cleft or nearly entire, inclosing the palet and large grain. (Bul- 

 bilis Raf .) 



1. Buchloe dactyloides (Nutt.) Engelm. Trans. St. Louis Acad. 1: 432. 

 1859. Culms 1-2 dm. high from a tufted leafy base, propagating chiefly by 

 runners: leaves flat, 1-2 mm. wide, attenuate: staminate spikelets in pectinate 

 spikes 1 cm. long or less; pistillate spikelets (rare) in terminal or axillary 

 clusters, subtended by inflated involucral sheaths. Formerly one of the im- 

 portant grasses of the plains, from Texas to Minnesota, but now rapidly dis- 

 appearing. 



42. SCLEROPOGON Philippi 



Slender stemmed grasses with short flat leaves, from matted rootstocks. 

 Spikelets dioecious (rarely monoecious), very unlike, narrowly paniculate: 

 .mate spikdrts compressed, linear, many (10-14)-flowered; glumes lan- 

 ceolate, acute, suboqual, nearly equaling the contiguous florets; lemma 3- 

 koothed or sul .entire, equaled by the palet: pistillate spikelets narrowly 

 cylindrical, 3 .Vflowered; glumes lanceolate, the upper larger; lemma rigid, 



