BROMUS COMMUTATUS. 
ScurapER. Kocw. Parnett. H. Watson. Hooker anp ARNOTT. 
PLATE LV. 
Serrafaleus commutatus, ParwaToRE. BaBinctTon. 
The Tumid Field Brome-Grass. 
Bromus—Food. Commutatus—Changed. 
A SOMEWHAT common species, growing in corn-fields and on 
road-sides. 
Stem upright, circular, smooth, and striated, carrying four or 
five flat, soft, sharp-pointed leaves, with striated sheaths, the 
upper sheath having an obtuse ragged ligule at its summit. 
Joints five. Inflorescence usually simple-panicled. Panicle when 
young upright, when more mature pendant. Branches rough. 
Spikelets linear-lanceolate, brownish purple, mostly of ten awned 
florets. Calyx consisting of two almost equal, broad acute 
glumes; margin membranous. Upper half of the keels dentate. 
Outer glume three-ribbed; inner glume seven-ribbed. Florets 
of two nearly equal-sized pale, the exterior one of basal floret 
oval, rough, glossy, and somewhat longer than the glumes; 
seven-ribbed. Inner palea linear-oblong, having two green mar- 
ginal ribs fringed with white hairs. Stigmas plumose. Length 
from nineteen to thirty-six inches. Root fibrous and annual. 
Bromus secalinus is more linear and longer. 
