IX] "seeds" 165 



visible. About 10 — 14 mm. long and narrowing somewhat 

 suddenly into the smooth stiff awn, shorter than itself. 

 Indications of a tooth at each side of the base of the awn. 

 Caryopsis somewhat flattened, thin and long, barge-shaped, 

 8 — 10 X 1'5 — 2 mm., pointed at both ends, brown, hairy 

 at the tip with the remains of the stigma. " Seed " often 

 purplish. Rachilla long and slender. 



Must be carefully distinguished from Brachypodium, which has 

 the palea less inrolled and a stouter rachilla. 



Bromus giganteus has a shorter and flatter " seed " and longer 

 awn. 



Bromus asper, Murr. (Fig. 71). 



Palea often reddish, 5 — 7 ribbed and usually roughly 

 hairy, mid-rib scaberulous, about 15 mm. long, linear- 

 lanceolate (barge-shaped), the tip more distinctly two- 

 toothed and tapering more gradually into the smooth 

 awn, about its own length. Eachilla distinct. Otherwise 

 resembling B. erectvs. 



B. giganteus has a shorter " seed " and longer awn. 



A A Palea scarcely hairy: awn up to twice its 

 length. 



Bromus sterilis. 

 B. giganteus. 



Bromus sterilis, L. (Fig. 50). 



Palea nearly smooth, somewhat inrolled, terete-lanceo- 

 late-acuminate, tough, red-brown, 12 — 15 mm. long, seven- 

 ribbed, with a long serrulate awn (20 — 30 mm. or more) 

 practically terminal. Ribs serrate. Caryopsis 9 — 10 mm. 

 long, flattened, thin. Rachilla distinct, smooth, much 

 wrapped in, widens upwards and is somewhat flattened. 



