ch. vn] Botanical Description of Species 



79 



from the central portion of the sheath only. Spikelets usually 

 pale green. Bare. 



Bromus. British members of this genus may be recognised 

 by the rather large several-flowered spikelets on a distinctly branched 

 panicle, and by the presence of an awn arising just below 1 the divided 

 apex of (he outer palea. The 

 leaf-sheaths are entire 2 and 

 usually hairy. All our native 

 species are inferior grasses and 

 should be considered as weeds 

 by the agriculturist. 



Bromus arvensis, L. (Field 

 Brome-grass.) (Fig. 67.) 



An annual or biennial, with 

 entire sheaths which are finely 

 striated and hairy. Shoot sec- 

 tion round; heel slight; blades 

 thin, dry, acutely pointed, and 

 hairy on both surfaces. There 

 are no auricles, and the ligule 

 is short, thin, and slightly 

 ragged. 



Flowers in May or June; 

 culms from lj to 3 feet high, 

 with considerably enlarged 

 nodes. Panicle rather open 

 and drooping. Spikelets linear- 

 lanceolate, containing about 

 nine flowers. Empty glumes 

 rather unequal, practically 

 smooth; the upper and larger 



one is seven-nerved, and its tip is midway between its base and 

 the top of the outer palea of the fourth flower of the spikelet. 

 The lower glume is three-nerved. (These last features will serve 

 to distinguish it from B. mollis.) Both glumes have membranous 



1 Except B. erectus and B. giganteus in which the awn may be considered as 

 terminal. 



2 Except in B. giganteus, see p. 85. 



Fig, 68. "Seed" 

 of Bromus ar- 

 vensis, L. x 5. 



Fig. 69. "Seed" 

 of Briza me- 

 dia, L. x 10. 



