Piper New and Interesting American Grasses. 145 



flowering from the base. Spikelets 7-9 mm long, on slender pedicels 

 which are usually abruptly curved and pubescent just at the points of 

 attachment. Perfect floret only one ; lower empty glume oblong, retuse, 

 silvery scarious in the apical third, 7 mm. long, five-nerved, only the mid- 

 nerve reaching the apex, the others anastomosing about the middle of the 

 glume ; upper empty glume oblong-linear, obtuse, 7 mm. long, five-nerved, 

 the lateral ones faint ; flowering glume oblong, truncate and retuse, 6 to 7 

 mm. long, thick and green for three-fourths its length, scarious at the apex, 

 eleven-nerved, the nerves rugose and anastomosing near the apex of the 

 thick part, the intermediate ones bearing a few bristles ; palet spatulate- 

 oblong, retuse, 4.5 mm. long, the nerves ciliate, the margins narrow ; sterile 

 floret clavate, pedicelled, reaching the apex of the palet. 



Santa Eulalia Mountains, Chihuahua, Pringle, No. 430, April 6, 1885 

 (Type) ; Chihuahua, E. Williamson, No. 342 in 1885 ; Sierra Mojada Mts., 

 Coahuila, M. E. Jones, No. 482, April 19, 1892. 



Heretofore mistaken for M. laxiflora Cav., a much taller Chilean species 

 which differs in having 2 to 3 perfect florets, acutish empty glumes, more 

 hairy 7-nerved flowering glumes and very scabrous sheaths. 



Poa brachyglossa sp. nov. 



Perennial ; whole plant pale or glaucescent, the panicle often somewhat 

 purple tinged. Culms terete, glabrous, smooth and firm, mostly 3-jointed, 

 60 to 100 cm. high. Sheaths smooth, glabrous, shorter than the interned es ; 

 ligules of the innovations very short, of the culm leaves 1 to 2 mm. long, 

 scarious ; blades rather stiff, acute, folded or involute, almost leathery in 

 texture, 5 to 20 cm. long. Panicle narrow, erect or nearly so, 10 to 20 cm. 

 long ; rays in 6 to 8 obscure series of 2 to 5, short, clustered, ascending, 

 somewhat scabrous. Spikelets oblong-linear, 7 to 10 mm. long, 3 to 6- 

 flowered, the florets appressed. Empty glumes smooth, thin, with broad 

 scarious margins, glabrous except the midnerve, which is scabrous above, 

 the lower lanceolate, acute, 4 to 5 mm. long, 3-nerved, the lateral ones 

 short, the upper ovate, 3-nerved, a little longer ; flowering glume elliptic- 

 ovate, obtusish, the sides much inrolled, smooth, or nearly so, quite firm in 

 texture, convex, faintly nerved, the lateral nerves disappearing in the 

 scarious apex ; palet oblong-linear, obtuse, the nerves ciliate-scabrous, the 

 lateral part half as broad as the internerve. 



This is the representative of Poa laevigata Scribn. west of the Rocky 

 Mountains. It is confined largely to somewhat alkaline soils, which it 

 often covers in nearly pure growths. The short ligules separate it at once 

 from any other species of the group, namely laevigata, lucida and 

 ncvadc.nsis. 



The following collections are representatives of Poa brachyglossa. The 

 type has smooth leaves and culms, but other specimens included differ 

 only in having both the culm and leaves somewhat scabrous. 



Washington: Douglas County, Sandberg & Leiberg 267, June 22, 1893 

 (Type) ; Coulee City, Piper 3917, 3916, 3918 ; Cold Creek, Cotton 402 ; With 

 out locality, Vasey 42 ; Wenas, Griffiths and Cotton 80 ; Loomis, Griffiths 



