146 



POACEAE 



Awns shorter than the flowering scales or wanting; perennials 

 5 dm. tall or more. 

 Leaf-sheaths strongly retrorse-hispid. 3. B. asper. 



Leaf-sheaths glabrous or softly pubescent. 



Flowering scales pubescent on the margins only. 4. B. ciliatus. 



Flowering scales pubescent all over the back. 5. B. purgans. 



Lower empty scale 3-nerved, the second one 5-9 nerved. 



Perennials; flowering scales densely pubescent with silky hairs. 

 Annuals. 



Flowering scales awned. 



Flowering scales pubescent with soft appressed hairs. 

 Flowering scales glabrous, or minutely roughened. 

 Awns straight. 



Fruiting scales with strongly inrolled 

 margins, the nerves obscure, leaf-sheaths 

 glabrous. 

 Fruiting scales with the margins not in- 

 rolled, the nerves prominent; leaf 

 sheaths pubescent. 

 Spikelets broadly lanceolate, usually 



over 6 mm. wide. 

 Spikelets lanceolate, usually less than 6 

 mm. wide. 

 Awns bent near the base, divergent. 

 Flowering scales awnless or awn-pointed, nearly as broad 

 as long. 



1. B. tectorum L. In fields and waste places: Me. to Ont., Md., 



Ohio and Mo. Naturalized from Europe. 

 Abundant as a weed. 



2. B. sterilis L. In waste places and on ballast: eastern Mass. 



to D. C, Ohio, Ark. and Colo. Native of Eu. and Asia. 

 Rare as a weed in our area. 



3. B. asper Murr. In waste places: N. B. to Mich, and Ky. 



Naturalized from Europe. 

 Rare as a weed in our range. 



4. B. ciliatus L. In woods and thickets: Newf. to Man., N. Y., 



N. J., Minn, and Tex. 



Conn. Rare along the coast, increasing northward. 



N. Y. Throughout, rare or wanting on L I., and S. I., increasing 

 northward. 



N. J. Northern Ocean and Monmouth counties, increasing north- 

 ward. 



Pa. Throughout. 

 Tertiary, o: Cretaceous, very rare: Older Formations, increasing 



northward. 117-207 days. Sea level-3,365 ft. 



6. B. Kalmii. 



7. B. hordeaceus. 



8. B. secalinus. 



9. B. racemosus. 



10. B. arvensis. 



11. B. squarrosus. 



12. B. brizaeformis 



