268 



3-nerved, with an awn about i line long; palet equaling its glume and nearly as 

 wide. 



Typo specimen collected by C. S. Sheldon on sandy soil, UtoPass, Green Moun- 

 tain Falls, El Paso County, Colorado, at 8,500 feet altitude, August 2, 1892 (No. 

 321). This species is nearest to AI. gracilis variety breviaristata Vasey, but is more 

 slender, with shorter leaves, shorter ghunes, and shorter awns. 



Bporobolus ligulatus Vasey & Dewey sp. nov. Perennial from a knotted root- 

 Btock; culms slender, smooth, simple, 12 to 18 incljes high; basal loaves numer- 

 ous, narrow, 1 line wide, 4 to 12 inches long, flat or convolute, scabrid or nearly 

 smooth; culm leaves 2 or 3; sheaths equaling or exceeding the long iuternodes, 

 the upper one extending nearly to the panicle; ligule 2 to 4 lines long, lacerate; 

 panicle 4 to 6 inches h)ng, narrow, erector noddiug, dark green ; branches mostly 

 single, erect or sprea^ling, hispid, spikelet-beanng nearly to the base, i to f 

 inch long; spikelets 1^ to 2 lines long, narrow, subterete; empty gluines broadly 

 lance-ovute, obtuse, nerveless, dark green, one-lialf as long as the floret, the 

 second slightly larger; floral glume laucc-oblong, subobtuse, smooth, 3- (or 

 obscurely 5-) nerved; palet like the glume iu texture, color, and size, with a nar- 

 row, obscure, membranaceous, margiual wing (usually involute) on each side of 

 the apex. 



Typo specimen in the United States National Herbarium; collected by G. C. 

 Ncallcy in Limpia Canon, Presidio County, Texas, September, 1892 (No. 127). 

 It is most nearly related to S. jotiesii Vasey, but may be readily distinguished 

 by its leafy culm and larger spikelets, 



Calamagrostis arctica Vasey, 111. N. A. Gr. ii.55(1893). Perennial; culms from a creep- 

 ing rootstock, decumbent, below, 6 to 10 inches high, the base covered with persist- 

 ent, open, leafless sheaths; radical leaves rather rigid, 2 to 3 inches long, flat, 

 smooth, 2 to 3 lines wide, the 1 or 2 cauline leaves with long, loose sheaths, smooth, 

 the blades erect, flat or folded, about 1 inch long; ligule acute, 1 to 1^ lines 

 long; panicle spike-like, about 1 inch long, rather dense; the short branches 

 spikelet-bearingto the base; spikelets 2 to 2^ lines long, purplish; empty glumes 

 ovate-lanceolate, attenuate-pointed, scabrous on the keel and nerves, the first 

 1-nerved, the second 3-nerved ; floral glume elliptical-oblong, acutely 4-toothed 

 at the broad apex, 4-nerved, about 2 lines long, the awn from near tlio base, 2i 

 to 3 lines long, and extending conspicuously beyond the empty glumes; palet 

 lanceolate, acuminate, 2-toothed at the apex, about equaling the floral glume; 

 hairs of the callus and pedicel one-fonrth as long as the floret. 



Type specimen collected by J. M. Macoun, in 1801, at St. Paul Island, Bering 

 Sea (No. 38). It bears some resemblance to C. montanensis Scribn., but is read- 

 ily distinguished by the broader leaves and the short, purple panicle. 



Bouteloua rothrockii sp. nov. Perennial, culms tufted, 15 to 20 inches high, 

 erect, simple or sparingly branched, leafy nearly or (piite to the panicle; leaves 

 narrow, thinly pubescent near the base, 2 to 5 inches long; ligule short, ciliate; 

 panicle 3 to 7 iuchos long, consisting of 5 to 9, nearly straight, erect, spreading 

 or recurved 8]>ike8, which are commonly 1 to 1^ inches distant, 1 to 1^ inches 

 long, and 2 lines wide, densely flowered; spikelets (including awns) 2 to 2^ 

 lines long; empty glumes unequal, oblong, mncronnte or acute, the upper 

 about 1 line long, the lower one-half as long; flornl glume oblong, 4-lobed to 

 the middle, villons on the nerves below, ciliate on tlio margins and apex, the 

 awns from the sinuses one-half longer than the glume; palet nearly as long as 

 its glume, wedge-oblong, 4-tooth«d or lobed above, with the two nerves ex- 

 tended into short awns; sterile pedicel ]iairy-tulte<l above, with 2 or 3 imper- 

 fect florets, and 3 awns as long as those of the perfect floret. 



Type specimens collected at Cottonwood, Arizona, by Dr. J. T. Eothrock, in 

 1874 (No. 347), and distributed with Pringle's Arizona collection of 1884 as B,poly- 

 stachya variety major Vasey. It is also found in New Mexico and. northwestern 



