THE GENERA AND THEIR SPECIES. 87 



Varieties — 



B. diandrus. Panicle erect ; paleae nearly equal, 



B. rigidns. Panicle compact ; rachis downy. 



67. B. arvensis. Ranging, mostly on clay soils, through 

 Europe and Central Asia. June to August. Root annual or 

 biennial, fibrous. Stems several, rooting from the lower nodes 

 erect, slender, hard, striated, leafy ; nodes four, hairy, covered by 

 sheaths. Leaves narrow, flat, downy, ribbed, edges rough. 

 Sheaths almost entire, keeled, hairs deflexed, shorter than leaves, 

 uppermost small ; ligule conspicuous, torn. Panicle erect, then 

 drooping, spreading, rough, half-whorled. Spikelets lanceolate, 

 glossy, drooping, florets seven or more, purple and white. Outer 

 glume the smaller, five-ribbed ; inner three-ribbed and often 

 slightly awned. Outer palea short, ovate, turgid, cleft at apex, 

 awn as long as glumes ; inner palea shorter than outer palea, 

 thin, white. Anthers yellow. 



Varieties — 



B. secalinus. Panicle loose, drooping, slightly com- 



pound. 



B. racemosus. Panicle long, erect, simple, plant glabrous. 



B. commutatus. Panicle loose, slightly drooping, plant 



glabrous; stem with five joints. 



B. mollis. Panicle close, erect, plant downy, leaves 



rolled in bud 



B. multi floras. Florets numerous, glumes broad. 



The Field Brome has been formed into a genus or sub-genus 

 of its own, of which its varieties form its species ; but as we are 

 following Bentham in our list we have to leave it as he left it. 

 This new genus Serrafalcus, or as Hackel has it, sub-genus, 

 Zeobromus, may be shortly described as consisting of annuals 

 with ovate or lanceolate spikelets, narrower above ; outer glume 

 with three to five ribs, inner with five to seven ; outer palea with 

 seven to nine, without keel and occasionally awnless ; inner 



