86 PANIOACEiE. 



P. furcatum viUosum Vasey. 



Culms containing 3-4 internodes above the root-stock, 50-80 cm. 

 high. Sheaths compressed ; blades thinly clothed with soft hairs, 

 flat, rough above, obtuse, 10-15 cm. long, 1 cm. wide. Spikes 

 3-3, narrow, 5-8 cm. long. Spikelets about one third longer than 

 the internodes of the rachis, ovate-lanceolate, less than 5 mm. long; 

 first glume 7-nerved, second 5-nerved, third 2.7 mm. long. 



Florida, A. H. Ciirtiss 3565, ticketed P. Digitaria Poir., G. V. 

 Nash 509. 



Swamps, North Carolina to Florida and other Southern States. 



3. P. membranaceum Walt. Fl. Car. 75 (1788), not Lam. 

 (1791). P. Walterianum Schultes, Mant. 2:166 (1824). 



Culms decumbent, from creeping rhizomes, much branched^ 

 20-60 cm. long. Sheaths rather loose; blades smooth, acute, 4-6 

 cm. long, 4 mm. wide. Spikes 3-6, approximate, the lowest ones 

 included by the sheath, about 2 cm. long, rachis thin, 2.5 mm. 

 wide, clasping the spikelets. Spikelets in two rows, in each row 

 overlapping for one half their length, oval, flattened, nearly 2 mm. 

 long, first and second glumes thin, 3-nerved or with two outer ob- 

 scure nerves. 



Maryland, Scrihner 3564 from Canby; Tennessee, U. S. Dept. 

 Agricul. 28 from Gattinger. 



New Jersey, Delaware, and Southern States. 



4. P. gracile Schlecht. Linnsa, 26:134 (1853-55). 



Culms diffuse or decumbent, much branched, 15-30 cm. high. 

 Sheaths rather loose, thickly pubescent; blade ovate-lanceolate or 

 linear-lanceolate, fiat, thin, sparingly pubescent, 2-5 cm. long. 

 Spikes 3-8, scattered, 1-2 cm. long, the lowest ones included by the 

 sheath, rachis thin, about 2 mm. wide, fiat or clasping the spikelets. 

 Spikelets in two rows, one each side the mid-nerve, those of each row 

 about 2 mm. apart, elliptical, 2.2-2.4 mm. long, first and second 

 glumes very thin, 3-nerved. 



Mexico, Pringle 3343. 



In appearance considerably like P. meinbranaceum Walt. 



5. P. mucronatum Muhl. Cat. 8 (1813). Ceresia fluitans Ell. 



