POACEAE 119 



2. C. carolinianus Walt. (C. tribuloides of many earlier authors, 

 not of L.). In dry sandy places: Me. to Wise, and Cal. 

 south to Fla. and Mex. ; also in the Bahamas and Mex. 

 Common in most parts of the range. 



19. Zizania [Gronov.] L. 

 1. Z. aquatica L. In swamps: N. B. to Man., south to Fla. and 

 Tex. 



Conn. Common near the coast, decreasing inland. 

 N. Y. On western L. I., rare on S. I., and scattered on the banks 



of and on islands in the Hudson, up to Greene Co. 

 N. J. Scattered throughout, except the pine-barrens, there not 



recorded. 

 Pa. Bucks, Philadelphia, Delaware and Chester counties. 



Tertiary, not on Beacon Hill, common elsewhere: Cretaceous, 

 common: Older Formations, decreasing northward. 159-220 

 days. About sea level. 



20. Homalocenchrus Wieg. 



Spikelets 2.5-3 mm. long; panicle-branches usually rigid. I. H. virginicus. 



Spikelets 4-5 mm. long; panicle-branches usually lax. 2. H. oryzoides. 



1. H. virginicus (Willd.) Britton. In swamps or wet woods: 



Me. to Ont., Fla. and Tex. 



Throughout the range, except in the pine-barrens, and east of 

 them, there not recorded. 



2. H. oryzoides (L.) Poll. In swamps and along streams: Newf. 



to Ore., south to Fla. and Tex. Also in Eu. and Asia. 

 Common throughout the range, except the pine-barrens. 



21. Phalaris L. 



Outer scales not winged; inflorescence a narrow panicle. 1. P. arnndinacea. 



Outer scales broadly winged; inflorescence a spike or spike-like 



panicle. 2. P. canariensis. 



1. P. arundinacea L. In moist or wet soil: N. S. to Br. Col., 



south to N. J. and Colo. Also in Eu. and Asia. 

 In most parts of our range. 



2. P. canariensis L. In waste places: N. S. to Ont., Va., Mo. 



and Colo. Native of Europe. 

 Locally rare as a weed. 



