46 MEMOIRS OF THE NEW YORK BOTANICAL GARDEN. 



along brooks at an altitude of 2500-3300 m. : but sometimes found 

 at an altitude of 2000 m. along the cold mountain streams. 



Montana: Lima, 1895, Shear, 662; Rydberg, 2j0j: Mystic 

 Lake, 22j^ and 22j6; Spanish Basin, 1896, Flodmaii^ 12^: Little 

 Belt Mts., near the pass, 12-/; near Barker, 126 ; Yogo, 1888, R. S. 

 Williams^ jy2 ; Mt. Blackmore, 1886, Tweedy, 1024; Old Hollowtop, 

 Pony, July 7, 1897, Rydberg & Besscy, j6iS^ 3^19 and 3626; 

 Spanish Basin, July 28, 3620 and J624; Cedar Mountain, July 16, 

 362J : Mt. Chauvet, July 29, j(5^/, j(5^j and jdj^; Spanish Basin, 

 1896, Rydberg, 3022; Bridger Canon, 321 j : Little Belt Pass, jj/p; 

 McDonald's Peak, iSS^t^Canby, jy^.: Upper INLirias Pass, 775. • Little 

 Belt Mts., 1883, Scribner, 388. 



Yellowstone Park: Soda Butte, 1885, Tzceedx, 628; Slough 

 Creek, 62"/; Electric Peak, August 20, 1897, Rydberg d- Bessev, 

 J622. 



* Poa longipila Xash. 

 Whole plant, with the exception of the flowering scales, smooth 

 and glabrous. Culms 3-4.5 dm. tall, erect, the upper portion naked : 

 culm with one leaf, or occasionally two leaves : sheaths commonly 

 elongated; ligule scarious, about 4 mm. long, broad, obtuse or acut- 

 ish ; blades erect, strict, firm, acuminate, 3-8 cm. long, 3-4 mm. 

 wide, slightly roughened above : panicle loose and open, 6-9 cm. 

 long, its finally widely spreading branches naked for the greater part 

 of their length, spikelet-bearing and dividing only at the summit, the 

 lower branches 3—4 cm. long and often reflexed : spikelets 6—8 mm. 

 long, ovate-lanceolate, acute, on very short pedicels ; scales usually 

 6, sometimes 5, purple, excepting the margins, acute, the lower 2 

 empty, the first i-nerved, the second 3-nerved, the flowering scales 

 5-6 mm. long, 5-nerved, the intermediate nerves faint, the inter- 

 nerves distinctl}^ appressed-pubescent below, the hairs growing 

 shorter and vanishing toward the apex, the lateral nerves and mid- 

 nerve copiously pubescent with long hairs, the former for about one- 

 half their length, the latter for about two-thirds, the longer hairs on 

 the midnerve about 1.5 mm. long, the crisped hairs on the callus 

 very copious and long, when straightened out 3-5 mm. long; palet 

 about four-fifths as long as the scale, ciliate on its 2 nerves. 



Yellowstone Park : Electric Peak, 1897, Rydberg, 3614. 

 *Poa purpurascens Vasey, Bot. Gaz. 6: 297. 



It has the short dense spike of P. epilis and P. Cusickii, but is 

 not a bunch grass. As in Poa alfina, it is characterized by its purple 

 flowers, but the plant is much taller, the glumes larger and more 

 acuminate. It grows at an altitude of 2500-3000 m. 



