294 BOTANY. 



Trisetum alpestre, Beauv.— This is chiefly distinguished from T. 

 swhspicatum by its slender, open, spreading panicle. It corresponds well 

 with European specimens of T. alpestre. — Twin Lakes, Colorado, 1873 

 (1174). — Plate XXVII. Fig. 4. Natural size. 5. Spikelet, magnified 6 

 diameters. 6. The same, with glumes removed. The figure should have 

 shown a slight pubescence on the pedicel of the upper floret. 



Trisetum Wolfii. — Culms erect from a decumbent base, l£-2° 

 high, smooth above; leaves flat, upper ones short, lower ones 4-6' 

 long, somewhat scabrous, ligule lacerate; flowers in an upright, close, 

 almost spicate panicle, which is 2-4' long, 1-2 rays at each joint ; spike- 

 lets lanceolate, 2-flowered, and with rudiment or continuation of the 

 rachis half as long as the upper flower, the rachis and filament villous; 

 glumes lanceolate, membranaceous, acuminate, equalling the flowers, 

 which have a few hairs at the base ; lower palet lanceolate, acuminate, 

 slightly split or 2-toothed at the apex, obscurely 5-nerved, bearing near 

 the point a straight appressed awn, equalling or a little exceeding the palet; 

 upper palet rather shorter; grain oblong-linear, nearly as long as the palets. 

 This obscure grass was collected by Mr. E. Hall in the Rocky Mountains, 

 and in his collection was mixed with Poa tenuifolia; it was also collected 

 by the writer in 1868, on the expedition of Major Powell, and distributed 

 as No. 693 in his collection. Very fine specimens were also collected in 

 Middle Park, Colorado, in 1874, by Prof. Gr. H. French. It is at least very 

 close to, if not identical with, Oraphephorum melicoides, some specimens of 

 which from Mount Kineo, Maine, show the short awn on the lower palet. — 

 Twin Lakes, Colorado, 1873.— Plate XXVII. Fig. 1. Natural size. 2. 

 Spikelet, magnified 5 diameters. 3. A floret, showing the palets and the 

 linear seed, enlarged 5 diameters. 



Aira c^spitosa, L., var. Montana. — The Rocky Mountain forms of 

 this species vary from the description in having involute instead of flat 

 leaves, but rather thick and coarse, unlike the bristle-form leaves of A. 

 flexuosa, and usually also in having longer awns than are described. — Utah, 

 1871 and 1872. South Park, Colorado, 1873 (1175). Willow Spring, 

 Arizona, 1874 (230). 



Hierochloa borealis, R & S.— South Park, Colorado, 1873 (1176). 



