‘ Graminaceae 65 
BROMUS BROME 
Annual or biennial or perennial. Leaves flat or nearly so. Spikelets numerous, 
5—15-flowered, oval to lanceolate; pedicels thickened at the tip; flowers perfect 
except the upper one. Glumes unequal, acute, the lower |—3-veined, the upper 3—9- 
veined. Lemma rounded or keeled on the back, 5—-9-veined, usually 2-toothed at apex, 
awnless or awned from just below the tip. Palet-keels ciliate. Stamens 3. Stigmas 
arising below the hairy cushion-like top of the ovary. Grain adherent. (Gk. broma—= 
food; Bromus was first the name of a wild oat.) 
A. Lemma-awn 0—16 mm. long. ‘ 
B. Lemma glabrous or merely scabrous. 
C. Spikelets strongly flattened. 
D. Lemma 6—11 mm. long. 
E. Leaf-sheath glabrous; lemma usually short-awned. W. E. 
B. secalinus L. (Chess) 
FE. Leaf-sheath pubescent; lemma usually awnless. E. 
B. brizaeformis F'. & M. (Quake Brome) 
DD. Lemma 12—18 mm. long. 
F. Lower glume 3-veined, 6—8 mm. long; lemma 7-veined. E. 
B. polyanthus Scribn. 
FF. Lower glume 5-veined, |12—-16 mm. long; lemma 9-veined. W. E. 
(B. hookerianus.) B, carinatus hookerianus Shear 
CC. Spikelets terete or nearly so. 
G. Awn of lemma bent or twisted, 10—12 mm. long.  E. 
B. japonicus Thurb. 
GG. Awn of lemma straight or none, often shorter. 
H.  Leaf-sheath glabrous or nearly so; lower glume |-veined; upper glume 
3-veined; rays of the panicle mostly 5—-7 in a bunch. W. E. 
B. inermis Leyss. (Hungarian Brome) 
HH. _Leaf-sheath pubescent; lower glume |—3-veined; upper glume 3—-9- 
veined. 
I. Upper glume 3-veined; perennial; rays of the panicle mostly 2—3 in a 
bunch. C. E. B. orcuttianus Vas. 
II. Upper glume 7—9-veined; annual or biennial; rays of the panicle 
mostly 3—5 in a bunch. 
J. Panicle dense, erect; lemma 9—10 mm. long. E. 
B. hordeaceus glabrescens Shear 
JJ. Panicle loose, spreading. 
K. Panicle 7 cm. or less long, erect; lemma 6—8 mm. long. W. 
B. racemosus L. (Upright Chess) 
KK. Panicle 15 cm. or less long, drooping; lemma 9—1I0O mm. 
long. W. E. 
B. racemosus commutatus Hook. 
BB. Lemma hairy. 
L. Spikelets much flattened. 
M. Lemma-awn none or less than 7 mm. long. 
N. Lemma obtuse, its awn O—I mm. long. E. 
B. brizaeformis F: & M. (Quake Brome) 
NN. Lemma acute, its awn 3—6 mm. long. 
O. Leaves linear-lanceolate, flat, pilose. 
