TT 
1 line long, ovate-lanceolate, acute; floral glume little shorter, oblong, obtuse, min- 
utely toothed at the apex; palet wanting.—A small species with the aspect of Aira, 
collected in the Yellowstone Park, Wyoming, by Miss Edith A. Ross. 
22, A. exigua Thurb. Bot. Cal. 1. p. 275, A dwarfish annual grass; the culms 1 
to 4 inches high, erect, flattened, sometimes branching near the base; leaves from 
an inch to 2 lines long or less, mostly convolute ; ligule about a line long, acute; 
sheaths very loose, striate; panicle half the length of the plant, included and at 
first narrow, at length open; lower rays about five, the others in pairs, the longer 
about an inch in length, bearing one to five flowers above the middle; spikelets 
i of a line long, the pedicels much enlarged just below ; empty glumes not pointed, 
aculeolate on the keel, and with minute scattered hairs all over; floral glume 
equaling the empty ones, 5-nerved, scabrous, with few very minute hairs, very acute 
at apex, the midnerve prolonged into a roughish awn four times longer than itself, 
inserted about one-fifth below the tip, which is split down to that point,forming two 
sete; palet wanting; stamens 1(?)—Foothills of the Sierras (Dr. Bolander). This 
species I have not seen. 
2. Palet at least one-third as long as its glume. 
A, Small species. 
93. A. humilis Vasey. Bull, Torr. Club, X. p. 21. Perennial, tufted; colms 
4 to 8 inches high, naked above, 1 to 2 leaves below the middle; radical leaves 
numerous, L to 3 inches long, very narrow, not rigid, erect; ligule short; pan- 
icle 1 to 14 inches long, linear, narrow, and few-flowered, the rays short, mostly 
two or three below, above in twos or single, appressed, the longer rays subdivided 
and with two to five spikelets each ; spikelets purple, less than a line long, empty 
glumes ovate-lanceolate, acute, smooth; floral glumes nearly as long as the outer 
ones, 5-nerved, minutely toothed at apex, unawned or minutely awned; palet 
hyaline, two-thirds as long as its glume.—Oregon (Cusick), Washington (Howell and 
Suksdorf). 
24, A. zequivalvis Trin. (Bot. Cal. p. 271.) (Deyeuxia equivalvis Benth.) 
Probably perennial; culm 10 to 18 inches high, slender, erect, smooth; leaves 
flat, the lower 4 to 6 inches long, 1 to 2 lines wide, the upper 2 to 3 inches long, 
smooth, pale green; upper ligules 1 line long; sheaths smooth, shorter than the 
internodes; panicle narrow, 2 to 3 inches long, loose, smooth, green or purple; rays 
mostly in fives below, somewhat distant, unequal, the larger 1 to 14 inches long, 
flower bearing from about the middle; spikelets about 1 line long, on pedicels mostly 
as long as themselves; empty glumes nearly equal, acute; floral glume acute, nearly 
as long as the empty ones; palet as long or nearly as long as its glumes, with a 
minute hairy rudiment about one-fourth as long (‘‘two-thirds as long,” Trinius), as 
tle floral glume.—Alaska, British Columbia, Washington, Oregon, Montana and Cali- 
fornia. ‘ 
B. Larger plants. 
95. A. alba Linn. (Gray’s Manual, 6th ed.p. 647.) (A. stolonifera Linn, ; A. vulgaris 
With.) Rootstocks creeping or stoloniferous; culm 1 to 24 feet high (sometimes less 
than 1 foot), often decumbent at base; leaves flat, 2 to 6 inches long, ligule long and 
acute or short and obtuse ; panicle 3 to 8 inches long, open, spreading in flower, more 
or less contracted afterward, the rays usually numerous and unequal, the longer, 1 to 
3 inches long, subdivided and flowering above the middle ;, spikelets about 1 line long ; 
the empty glumes nearly equal; floral glume a little shorter than the empty ones, thin, 
3- to 5-nerved, awnless or rarely short: awned ; palet one-third to two-thirds as long 
as its glume.—Cultivated from Europe, but apparently also native in mountainous 
regions. 
