84 GEAMINEAE (GRASS FAMILY) 



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

 low. — <^olorado 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.) Foum. 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. BECKMANinA Host. 



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

 Spikelet* 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 Engehn. 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; glimies 1-nerved, subacute, the second larger but 

 shorter than the florets; lemma 3-nerved, sUghtly 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-cldf t or nearly entire, inclosing the palet and large grain. — {Bid- 

 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 PhiKppi 



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

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

 staminate spikelets compressed, linear, many (10-14)-flowered; glumes lan- 

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

 toothed or subentire, equaled by the palet: pistillate spikelets narrowly 

 cylindrical, 3-5-flowered; glumes lanceolate, the upper largpr; lemma rigid, 



