AGROSTIDE.E. 227 



the second reaching nearly to the base of the panicle, third 12-18 

 cm. long, sometimes extending beyond the panicle. Panicle but 

 little exserted, open, 10-20 cm. long, rays in twos or threes, the 

 half whorls 3-4 cm. distant, flower-bearing along the upper third. 

 Empty glumes dull green, tinged with purple, equal, or the first a 

 little longer, elliptical-lanceolate when the apex is spread, strongly 

 3-nerved, 6-7 mm. long; floret narrowly elliptical, 5 mm. long 

 from the short scarcely acute callus to the joint of the awn, clothed 

 with prominent white silky hairs over 1 mm. long; awn slightly 

 twisted and bent, about 2 cm. long, caducous. 



California, Bolander CI 16, seen by Scribner. 



Montana, Scribner in 1883. 



5. 0. Mongolica (Turcz.) Beal, Coult. Bot. Gaz. 15: 111 (1890). 

 Stipa MongoUca Turcz. Trin. Bull. Soc. Acad. St. Petersb. 1 : 67 

 (1836). 



A slender erect grass, about 30 cm. high. Sheaths shorter than 

 the internodes; ligule 2 mm. long; blades rigid, very slender, in- 

 volute, 2 in number, those of the sterile shoots half as long as the 

 plant, those of the culm 3-5 cm. long. Panicle exserted, loose, fcAV- 

 flowered, 4-8 cm. long, the lower rays in twos or threes. Empty 

 glumes membranous, subequal, jmrplish, obtuse^ 5-6 mm. long, 

 first 3-nerved, second 3-5-nerved ; floral glume slightly hairy, about 

 4.5 mm. long including the short almost obtuse callus, and the 2- 

 toothed apex; awn irregularly bent and plumose throughout, the 

 longest hairs below and nearly 2 mm. long; palea as long as its 

 glume or longer. Stamens 3. 



Mountains of Colorado, Hall and Harhonr 646. 



6. 0. exigua Thurb. Wilkes Expd. 481 (1854). 



Culms very slender, 15-30 cm. high, Ligule not ciliate, about 

 3 mm. long; blades scabrid, those of the culm 1-6 cm. long, those 

 below 6-15 cm. long, all of them conduplicate and cylindrical, 

 threadlike. Panicle exserted, very simple and narrow, 2-5 cm. 

 long, containing 4-8 spikelets. Spikelets linear-oblong, about 5 

 mm. long, the awn rather stout, curved when mature, and some- 

 what persistent, nearly as long as the spikelet, empty glumes sub- 

 equal, oval, a little shorter than the floret, acute or irregularly 



