290 BOTANY. 



is supposed to be the Poa Andina of Nuttall, is exceedingly variable and 

 puzzling. It embraces several varieties, two of which are represented in 

 this collection, viz : Var. spicata. — Radical leaves rigid, involute, scabrous, 

 pungently pointed, 3 to 9' long ; panicle narrow and spike-like ; branches 

 sessile or nearly so. — Colorado, J 873 (1135, 1136, 1137). Var. major. — 

 Panicle oblong ; branches short ; flowers larger and paler. — Arizona, 1872; 

 Colorado, 1873 (1133, 1134). 



Poa tenuifolia, Nutt. (Watson's Botany 40th Parallel, Synopsis Flora 

 of Colorado). — This species presents a great variety of forms, some of 

 which may yet require to be made distinct species. The general characters 

 may be stated as follows: culms tufted, 1-2^° high, stout or slender, 

 glabrous or with the leaves and sheaths more or less scabrous ; leaves 

 narrowly linear, 1-10' long, ligule short or elongated ; panicle erect or 

 slightly bending, narrow or somewhat open and spreading, 2-6' long; 

 branches 2-5 together, scabrous, of unequal length ; spikelets 2-5-flow- 

 ered, glumes keeled, lanceolate or ovate-lanceolate, acute, scarious-mar- 

 gined, upper one 3-nerved, lower 1-nerved; flowers very narrow, linear or 

 linear-lanceolate, scarcely keeled, convex on the back, obtuse or acutish, 

 scarious, and bronze-tinged at the apex, puberulent or finely pubescent, 

 obscurely nerved, not webbed ; flowers readily separating at the joints. 

 The grain is extensively gathered by the Indians for food. The following 

 forms or varieties occur in the collection: Var. kigida, Nevada, 1872, 

 Colorado, 1873 (1138 and 1140) ; var. elongata, panicle linear, 5-6 inches 

 long; Nevada, 1872; Colorado, 1873 (1141). 



Poa pratensis, L.— Colorado, 1873 (1125) ; Santa Fe", N. Mex., 1874 

 (19) ; and, what seems to be a slender form, in bogs, Twin Lakes, Colo- 

 rado, 1873 (1131). 



Poa serotina, Ehrh. — Twin Lakes, Colorado, 1873 (1130) ; also var. 

 laxicaule, Twin Lakes, Colorado, 1873. 



Poa c^sia, Sm. ?, var. rigida. — Mosquito, Colorado, 1873 (1142); 

 South Park, Colorado, 1873 (1143). 



Poa laxa, Haenke ?— Colorado, 1873 (1128). Var. minor, Hall's 

 post-office, Colorado, 1873 (500, J. Wolf). 



Poa flexuosa, var. occidentalis. — Twin Lakes, Colorado, 1873 



