532 
minutely scabrous; ligule scarious, acute, about 2 lines long, decurrent; leaf blade 
flat, 1 to 3 lines wide, those of the culm 1 to 3 inches long, those of the sterile shoots 
6 to 10 inches long, midnerve prominent beneath, smooth on both surfaces except 
near the rigid acute tips; the distinctly cartilaginous margins scabrous. Panicle 2 
to 4 or 5 (usually about 3) inches long, the scabrous branches at first nearly erect, 
widely spreading in anthesis; spikelets 3- to 5-flowered, 3 to 4 lines long, usually 
much longer than the rough pedicels; empty glumes nearly equal, 3-nerved, broadly 
lanceolate, acute with scarious margins and tips, the keel of the larger second glume 
scabrous near the apex; flowering glumes oblong, obtuse, 5-nerved, with scarious 
margins, silky-hairy on the nerves to near the middle and pubescent all over on the 
dorsal surface near the base, minutely scabrous in the upper part; palea as long as 
the glume, ciliate-scabrous on the keels, villous near the base. 
It has been doubtfully referred to P. pratensis. From this it differs in its longer 
and acute ligule, its larger spikelets, and its less strongly compressed glumes, which 
have broader scarious margins and no cobweb at the base. It resembles also, 
somewhat, P. alpina, but dilfers in its larger size, long, creeping rootstock, long, acute 
ligule, and empty glumes not conspicuously crested on the keel. 
Hot Springs, altitude 1,050 m., June 13; Custer, altitude 1,650 m., July 16 (No. 1151). 
No. 1272 from the Sand Hills of central Nebraska is the same. It has also been col- 
lected by John Macoun at Cypress Hills, British America, in August, 1880, and by 
Mrs. 8. B, Walker at Castle Rock, Colo., in 1890, 
Poa pratensis L. Sp. Pl. i, 67 (1753). 
A variable species, the extreme forms of which seem very different from each other. 
One form, very low and tufted with very narrow leaves and small spikelets, was found 
near Lead City, altitude 1,600 m., July 6 (No. 1153). A form 5 to & dm, high, with 
broad and long leaves (15 to 20 em. long and 6 min. wide), and very large spikelets 
was collected at Hot Springs, altitude 1,050 m., June 13 (No. 1156). A similar one, 
but with narrow panicle as in P, serotina, was found in Elk Canyon, altitude 1,200 m., 
June 30 (No, 1157), These are perhaps distinct from P. pratensis. 
Poa nemoralis L. Sp. Pl. i, 69 (1753). 
Several forms were collected, which have all been referred to this species by Pro- 
fessor Scribner. One is a low plant approaching variety stricta, but having a more 
open panicle, It resembles 2. cwsia collected by Rusby in Arizona. Hot Springs, 
altitude 1,050 m., June 14 (No. 1155). A form that by several has been mistaken for 
P. serotina was collected at Lead City, altitude 1,600 m., July 6; Custer, altitude 
1,700 m., August 1 (No. 1158). It has stiff leaves and spreading panicle. P. serotina 
of C.C. Parry’s collection and perhaps of Watson, King Survey collection, is the 
same. Another form is like the last, but with smaller and light-colored spikelets 
and broader, more flaccid leaves. In a wet place: Rapid City, altitude 1,000 m., 
June 25 (No. 1159). A slender form with spreading panicle, small, light-green spike- 
lets, and longer pedicels was mistaken for P. alsodes, Lead City, altitude 1,600 m., 
July 6 (No, 1160). 
Panicularia nervata (Willd.) Kuntze, Rev. Gen. Pl. ii, 783 (1891); Poa nervata 
Willd. Sp. Pl. i, 889 (1798). 
In wet meadows: Whitewood, altitude 1,100 m., July 7 (No. 1161). 
Panicularia americana (Torr.) MacMillan, Metasp. Minn. Val. 81 (1892); Poa 
aquatica americana Torr. Fl, U.S. i, 108 (1824). 
In ponds, above Custer, altitude 1,650 m., July 16 (No. 1163). 
Pestuca ovina L. Sp. PL. i, 73 (1753) var. 
The specimens are low, with a narrow panicle, and short, narrow leaves. It 
resembles the variety psevdo-ovina Hack, It grows in bunches on dry prairie. Lead 
City, altitude 1,600 m., July 4 (No. 1164), 
