Bit ONUS COMMUTATUS. 165 



BROMUS COMMUTATUS. 



SCHRADER. KOCH. PARNELL. H. WATSON. HOOKER AND ARNOTT. 



PLATE LV. 

 Serrafalcus commutatus, PARLATORE. BABINGTON. 



The Tumid Field Brome-Grass. 

 Bromus Food. Commutatus Changed. 



A SOMEWHAT common species, growing in corn-fields and on 

 1\. 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 keela 

 dentate. Outer glume three-ribbed; inner glume seven-ribbed. Florets 

 of two nearly equal-sized palese, the exterior one of basal floret oval, 

 rough, glossy, and somewhat longer than the glumes; seven-ribbed. 

 Inner palea linear-oblong, having two green marginal 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. 



It flowers in the middle of June, and ripens its seed at the com- 

 mencement of July. 



The specimen figured was gathered at Yonk, by Mr. Joseph Sidebotham, 

 of Manchester. 



