Graminaceae 45 
GASTRIDIUM 
Annual. Leaf-blades flat. Spikelets in a close tapering spike-like panicle. Rachil- 
la jointed above the glumes, extending beyond the perfect flower as a short bristle. 
Glumes persistent, very acute, enlarged, shining, swollen at base, concave below, keeled 
above, awnless (ours), the first longer than the second. Lemma about 14 as long as 
the second glume, with a tuft of very minute hairs at base, hairy on back, truncate-den- 
tate at apex, usually awned (so in ours); awn slender, twisted, on the back below the 
apex, exceeding the spikelet. Palet as long as its lemma. Stamens 3. (Gk. gastros—= 
belly or stomach, eidos—like; glume is swollen at base.) U. (G. australe.) 
G. lendigerum Gaud. (Nit-grass) 
CALAMAGROSTIS REED-GRASS: 
Mostly perennial. Leaf-blades flat or rolled up or hair-like. Spikelets in narrow 
and spike-like to open and spreading panicles. achilla jointed above the glumes, 
usually extending beyond the base of the lemma as a bristle. Glumes persistent, keeled, 
awnless. Lemma usually shorter than the glumes, very thin, wide, usually with a tuft 
of hair at base, awned, 5-veined below the awn; awn. dorsal, usually bent and twisted, 
rarely short and straight. Palet thin, more than '4 as long as the lemma, faintly or 
prominently 2-vemned. Stamens 3. Stigmas plumose. Grain sometimes partially ad- 
hering. (Gk. kalamos—a reed, agrostis—=a grass.) 
A. Awn of lemma bent; hairs at base of lemma 1/2 its length or less (in C. howellii 
over 14). ‘ 
B. Awyn shorter than the glumes, or projecting beyond them not more than 2 mm. 
C. Spikelets 3—4 mm. long; glumes not strongly keeled; lemma 2.5—-3.5 mm. 
long; not seashore plants. 
D.. Panicle pale-green. E. (C. suksdorfii luxurians. ) 
C. suksdorfii Scribn. 
DD- Panicle purple.- C: E. 
C. rubescens Buckl. 
CC. Spikelets 5—6 mm. long; glumes strongly keeled; lemma 5 mm. long; sea- 
shore plants. W. C. aleutica Trin. (Seashore Reed-grass) 
BB. Awn exceeding the glumes by 3 mm. or more. 
E. Panicle dense, almost or quite spike-like; leaves not setaceous, not nearly 
reaching the-panicle; awn projecting not over |!/y times the length of the lemma. 
F. Leaves soft, flat. °C. 
C. tweedii Scribn. 
FF. Leaves hard, closely rolled up. 
G. Glumes scabrous all over. C. E. 
C, purpurascens R. Br. (Purple Reed-grass) 
GG. Glumes nearly smooth. W. C. 
C. vaseyi Beal 
EE. Panicle loose; leaves setaceous, nearly reaching the panicle; awn often 3 
times as long as the lemma. W. C. 
C. howellii Vas. 
AA. Awn of lemma straight or rarely none; hairs at base of lemma more than !/ its 
length (in C. cusickti about 142). 
H. Panicles contracted, narrow, the short branches erect after flowering. 
I. Lemma with few hairs at base. 
J. Leaf-blade soft, not rigid. 
