$6 Flora of the Paloust Region 



B. sterilis L. Annual, the stout culms .5-1 m. high, usually decumbent 

 at base: panicle 10-20 cm. long, loose and drooping, its branches in whorls 

 of 2-6, long and slender, usually bearing but one spikelet: spikelets droop- 

 ing, 2.5-3.5 cm. long, 6-10-flowered: flowering glume narrowly lanceolate, 

 17-20 mm. long, bearing a stout rough awn, 2-3 cm. long. In waste places, 

 infrequent. 



B. tectorum L. Annual, 20-60 cm. tall, mostly erect, panicle one-sided, 

 drooping, the slender branches in threes and fours, and bearing several 

 spikelets above the middle: spikelets nodding, 15-20 mm. long, rather dense: 

 flowering glume lanceolate, pubescent, n-13 mm. long, the awn 13-15 mm. 

 long. Sparingly introduced in waste places. 



B. vulgaris Shear. Perennial: the culm slender, .8-1 m. tall: leaf blades 

 15-25 cm. long, glabrous or sparsely pilose; sheaths pilose with spreading 

 or reflexed hairs; ligule truncate, fringed, 3-5 mm. long: panicle sparse, 

 more or less nodding, 8-12 cm. long, spikelets 2-3 cm. long, 3-4 mm. wide: 

 flowering glume 8-10 mm. long, sparsely pubescent on the back, somewhat 

 ciliate on the margin, the awn 6-9 mm. long. In woods, Thatuna Hills. 



B. marginatus Nees. Perennial, tufted: the stout culms about 1 m.high: 

 leaf blades coarse, sparsely pubescent, 15-25 cm. long, rather narrow, the 

 branches in whorls of 2-4, about 7 cm. long, and bearing two spikelets: 

 spikelets 2.5-4 cm. long, 5-7 mm, wide, compressed and keeled, 7-9-flowered: 

 flowering glume rough pubescent, 1 1-14 mm. long, 2-toothed at apex, and 

 bearing a stout awn 4-7 mm. long. 



var. latior Shear. Larger and stouter, 1-1.5 m. tall: panicle 20-30 cm. 

 long; the lower branches 10-20 cm. long. 



The tvpical form occurs mostly in mountain woods; the variety is com- 

 mon at the edges of wheat fields, roadsides, etc. 



50. AGROPYRON. 



Inflorescence of terminal spikes: spikelets 3-many-flowered, 

 sessile, single and alternate at each notch of the usually continuous 

 rachis, the side of the spikelet turned toward the. rachis: flowering 

 glumes rigid, rounded on the back, 5-7-nerved, usually acute or 

 awned at the apex: palet often with hairy keels: grain pubescent 

 at the apex. 



Densely tufted, the short innovations usually not exceeding the sheath. 



A. DIVERGENS. 

 vStoloniferous, the innovations exceeding the sheath. 



Flowering glumes pubescent. A. ELMERi. 



Flowering glumes merely scabrous. A. pseudorepens. 



A. divergens Nees. Culms .5-1 m. tall, densely tufted, glabrous and 

 glaucous: culm leaves 3, the blades becoming strongly involute, minutely 

 pubescent above, scabrous beneath, the sheaths smooth or pubescent: spikes 

 erect, 5-15 cm, long: spikelets regularly scattered, lanceolate-oblong, 1-1.5 

 cm. long, without the awns: flowering glumes tipped with stout divergent 

 awns, 1-2 cm. long. 



var. inermis Scrib. & Smith. Culms usually more slender: spikelets 

 smaller: awns wanting. 



Very abundant on dry hills and exposed ledges. Both the typical form 



