276 GRASSES OF BRITAIN. 



Bromus ARVENSIS. 



Long-anthered Brome- Grass, 



Plate CXXVI. 



Specific Characters. — Panicle spreading. Palese equal. Outer 

 palea seven-ribbed. Anthers four times as long as broad. 



Descnptioji. — Root annual, fibrous, producing many stems, from 

 nine to eighteen inches in length. Sterns erect, round, hard, nearly 

 solid, smooth except just below the panicle ; bearing four or five 

 leaves with striated sheaths shorter than their leaves, the upper sheath 

 smooth or nearly so, the lower ones soft and pubescent. Ligules pro- 

 minent and jagged. Joints usually four, more or less hairy, mostly 

 covered by the sheaths. Leaves narrow, flat, rough on the margins, 

 hairy, especially on the upper surface. Liflorescence simple panicled, 

 at first erect, spreading when in fruit, and at length somewhat droop- 

 ing ; the rachis and branches rough. Spikelets linear-lanceolate, not 

 hairy, usually of seven florets, awned, and frequently tinged with 

 reddish-brown. Apex of large glume situated half-way between 

 the base of the glume and the summit of the second floret on the same 

 side, (see Fig. 1.) Glumes two, unequal, membranous at the mar- 

 gins, roughish on the keels ; outer glume the smaller, three-ribbed ; 

 inner glume five-ribbed, and often somewhat awned by a slight elon- 

 gation of the middle rib. Florets of two palese ; the outer palea of 

 lowermost floret longer than the glumes, seven-ribbed ; the two marginal 

 ribs the most distinct ; the summit either bifid or entire, membranous, 

 and glossy at the margins, the breadth equal to half its length, and, 

 when opened, the margins above the centre exhibiting an obtuse 

 angle, (Fig. 4) ; inner palea equal in length to the outer, thin, 

 acute, white, and membranous, furnished with two green ribs fringed 

 with stout white hairs. Aw7is erect, rough, slightly spreading when 

 dry, arising from a little beneath the summit of the outer palea, and 

 rather longer than the palea, except in the lowermost floret. Ova- 

 rium hairy on the summit. Strjles two, short, arising from the side. 

 Stigmas feathery. Filaments three, slender. Anthers long, notched 

 at each end. 



Obs. — Bromus arvensis is distinguished from Bromus commutatus 



Bromus arvensis, Linnaus, Koch, Smith, Babington, (not Hooker.) 



