272 GRASSES OF BRITAIN. 



Bromus COMMUTATUS. 



Taper Field Br ome- Grass. 



Plate CXXIV. 



This grass is the same as the one previously described in page 

 115, and figured in Plate XLIX. under the name oi Bromus arvensis, 

 which ought to have been named Bromus commutatus* It is distin- 

 guished from the Bromus arvensis of Linnaeus, (Plate CXXVI.,) in 

 the inner palea being shorter and more obtuse, not reaching further 

 up than to the base of the awn ; awns not so long as their florets ; 

 and the anthers small ; — whereas in Bromus arvensis the inner palea 

 is equal in length to the outer palea ; aims longer than their florets, 

 except the lowermost ; and the anthers about four times as long as 

 broad. 



Bromus commutatus is distinguished from Bromus patulus (Plate 

 CXXVII.) in the outer palea having seven ribs, and all the florets 

 longer than their awns ; — while in Bromus patulus the oiiter palea 

 has nine ribs ; and all the florets are shorter than their awns, except 

 the lowermost. 



Bromus commutatus is distinguished from Bromus squarrosus (Plate 

 CXXVIII.) in the outer palea being twice as long as broad, and hav- 

 ing seven ribs ; axons erect ; — whereas is Bromus squarrosus the outer 

 palea is not twice as long as broad, and has nine ribs ; aivns diva- 

 ricating, and arise further down from the summit of the outer palea. 

 The accompanying figure was drawn from a specimen gathered 

 near Edinburgh, 



Explanation of Plate CXXIV. Bromus commutatus^ natural 



size- 

 Fig, 1. Spikelet, showing the two glumes and eleven florets. 



2. Glumes. 



3. Floret, showng the two pale*. '^ 



4. Outer palea opened, shomng the seven ribs, 



5. Inner palea fringed, 



6. Ligule of upper sheath, 



7. Ovarium, pistils, stamens, and scales. 



Brorrms commidatus, Schrader, Koch. Serrafalcus commitatus, Parlatore, Babington. 

 * See a valuable paper on the Bromi, by Mr Wateon, in Lond. Journ. Bot,, i, 82, 



