HITCHCOCK AND CHASE NORTH AMERICAN PANICUM. 



165 



of this group; first glume one-third to half the length of the spikelet; second glume 

 and sterile lemma equal, faintly nerved; fruit 1.3 mm. long, 0.6 to 0.7 mm. wide, 

 elliptic, subacute, not umbonate. 



Autumnal form a dense mat with panicles scarcely rising above the leaves. 



This species is variable as to pubescence. Some of the specimens from Cuba and 

 Guatemala show only a few scattered hairs upon the surface of some of the blades, 

 but these are conspicuously ciliate on the margin. 



Fig. 155.— Distribution of P. strigosum. 



DISTRIBUTION. 



Sandy woods, Virginia and Tennessee to Florida and Louisiana; also in Mexico, 

 Guatemala, and Cuba. 



Virginia: Norfolk County, Kearney 1761. 



North Carolina: Roanoke Island, Chase 3244; Onslow County, Chase 3171; 



Wilmington, HitchcocJc 1450, 



Kearney 282. 

 South Carolina: Aiken, Ravenel. 

 Florida: Jacksonville, Curtiss 



3597*, 4031; Washington 



County, Comhs 567, 584. 

 Tennessee: White Cliff Springs, 



Scribner in 1890 (Hitchcock 



Herb.). 

 Alabama: Cullman County, Eg- 



gert21; Gateswood, Tracy 8422; 



Flomaton, Hitchcock 1043. 

 Mississippi: Saratoga, Tracy 8402. 

 Louisiana: Lake Charles, Hitchcoch 1162. 

 Mexico: Minatitlan, J. G. Smith 555 (Hitchcock Herb.). 

 Guatemala: Secanquim, Pittier 257; Cuesta de Peixha, Pittier 1800. 

 Cuba: El Guama, Palmer & Riley 213; without locality, Trn^^i-3875 in part. 



Angustifolia. — Plants mostly dull grayish-green, cespitose; vernal culms erect or 

 ascending from a spreading base, mostly 30 or 40 cm., rarely as much as 100 

 cm. high, appressed-villous at base or sometimes above, or rarely smooth 

 even at base; ligules ciliate, less than 1 mm. long; blades narrow, ascending, 

 usually firm and rigid, more or less striate with prominent nerves, and some- 

 times longitudinally wrinkled besides, often ciliate at the base; spikeleta 

 attenuate at base^ rather strongly 7-nerved, usually pubescent, the hairs aris- 

 ing from bullate papillae; first glume narrow and sheathing at base. Autum- 

 nal culms repeatedly branching, forming bushy crowns, these remaining 

 erect or becoming decumbent or widely spreading; blades much reduced, 

 often involute; a distinct rosette of basal leaves formed in the fall. Species 

 of the Atlantic Coastal Plain. 



Nodes bearded ; plants grayish -villous; autumnal blades flat. 

 Spikelets 2 mm. long 



92. 



Spikelets 2.5 to 2.8 mm. long. 



93. 



jla- 



Nodes not bearded; plants villous only at base, or nearly : 

 brous; autumnal blades involute or flat. 

 Autumnal blades flat; lower panicle branches spreading 



or deflexed 94. 



P. chry s opsi- 



difolium. 

 P. consangui- 



neum. 



P. angustifolium. 



