76 POACEAE 



37. Paspalum glabi^tum (Engelm. ) C. Mohr. Whole plant often glaucous. Stems 

 usually 1-2 ra. tall, stout, leafy : leaf-sheaths glabrous, or sometimes sparingly pubescent, 

 the external basal ones sometimes liirsute ; blades glabrous on the lower surface, the upper 

 surface glabrous or more or less hirsute, the lower blades 3-7 dm. long, 6-15 mm. wide : 

 racemes usually 3-6, sometimes 2, erect or nearly so, the lower ones commonly 1-1.5 dm. 

 long, occasionally shorter or longer: spikelets singly disposed or in pairs, 3.5-4.5 mm. 

 long, 2.75-3.5 mm. wide, the 2 outer scales glabrous, 3-nerved. 



In low ground, Maryland to Kansas, Georgia and Texas. Summer and fall. 



38. Paspalum Floridanum Michx. Stems 9-12 dm. tall, rather stout> leafy : leaf- 

 sheaths densely hirsute witli long hairs ; blades densely hirsute above and usually also on 

 the lower surface, the lower ones 3-6 dm. long, 6-10 mm. wide : racemes commonly 2 or 

 3, rarely 4, erect, the lower ones usually 8-12 cm. long : spikelets usually singly disposed, 

 8.5-4 mm. long, 2.5-3 mm. wide, the 2 outer scales 3-nerved, glabrous. 



In low ground. South Carolina to Florida, west to Texas. Summer and fall. 



39. Paspalum giganteum Baldw. Stems tufted, 1-1.5 m. tall, stout: leaf-sheaths 

 glabrous ; blades erect, glabrous on botli surfaces, if ciliate on the margins the hairs short, 

 the lower leaves 2-3 dm. long, 1.5-2 cm. wide : racemes 3-5, finally widely spreading, 

 1-1.5 dm. long: spikelets in pairs, about 3.25 mm. long and 2.5 mm. wide, the 2 outer 

 scales glabrous, 3-nerved. 



In ditches and swamps, Florida. Summer. 



40. Paspalum longicilium Nash. Stems tufted, ascending, stout, 6-12 dm. tall : 

 lower leaf -sheaths densely papillose-hirsute with long shaggy hairs ; blades glabrous on both 

 surfaces, the margins ciliate with very long hairs, the lower blades 2-4 dm. long, 1-2 cm. 

 wide : racemes ascending, the lower ones 8-17 cm. long : spikelets usually singly disposed, 

 3-3.3 mm. long and 2-2.3 mm. wide, the 2 outer sca:'les glabrous, 3-nerved. 



In clay soil in ditches, central peninsular Florida. Summer. 



41. Paspalum Buckley^num Yasey. Stems erect, 6-8 dm. tall : leaf -sheaths 

 smooth and glabrous ; blades 4-20 cm. long, 2-4 mm. wide, rough above, smooth beneath : 

 racemes erect, 2-4, 5-7 cm. long, the rachis straight, broadly winged, 1.5-2 mm. wide: 

 spikelets in pairs, often so crowded as to appear as if in 4 rows, 3 mm. long, about 1.5 mm. 

 broad, elliptic, the 2 outer scales 3-nerved, densely appressed-pubescent, the flowering scale 

 yellowish at maturity, faintly pitted in fine longitudinal lines. 



Jin low grounds, Texas. Summer and fall. 



42. Paspalum lividum Trin. Stems 6-10 dm. tall : leaf-sheaths compressed, 

 keeled, smooth, glabrous, except on the margins ; blades 3 dm. long or less, 3-5 mm. wide, 

 more or less pubescent on the upper surface : racemes 3-7, erect or ascending, 2.5-5 cm. 

 long, the rachis often setiferous on the margins : spikelets bright green, in pairs, elliptic, 

 acute or acutish, about 2.5 mm. long and 1.5 mm. wide, the 2 outer scales 3-nerved, gla- 

 brous, the third scale yellowish white, only slightly convex in cross-section. 



In wet places, Texas. Also in Mexico and South America. Summer. 



43. Paspalum praecox Walt. Stems tufted, compressed, 6-12 dm. tall : leaf-sheaths 

 compressed, the lower ones purple, the exterior basal ones hirsute, the remainder glabrous ; 

 blades 2 dm. long or less, 4-6 mm. Avide, glabrous: racemes usually 4 6, rarely more or 

 fewer, ascending, 2-5 cm. long : spikelets in pairs, lenticular, nearly fiat on the inner side, 

 yellowish green, orbicular to oval, 2.2-2.6 mm. long, 1.8-2.2 nun. wide, the 2 outer 

 scales glabrous, 3-nerved, the third scale striately roughened with conspicuous papillae. 



In moist or wet places, South Carolina to Florida and Texas. In spring and early summer ; some- 

 times also in the late fall. 



44. Paspalum glab^rrimum Nash. (Ilabrous. Stems single, about 1 m. tall, erect, 

 compressed : leaf-sheaths compressed ; l^lades erect, long-acuminate, the larger 3-4 dm. 

 long, 5-8 mm. wide, the upper blade very short or wanting : racemes 3 or 4, ascending, the 

 lower 4-7 cm. long : spikelets nearly circular, barely if at all convex on one side, 3 mm. 

 long, light green, tlie 2 outer scales 3-nerved. 



In low pine lands, southern peninsular Florida. Summer. 



45. Paspalum tardumi Nash. Stems not tufted, compressed, usually 6-13 dm. tall : 

 leaf-sheaths compressed, the outer basal ones densely papillose-hirsute with long hairs, the 

 remainder similarly jiubescent with very long hairs at the apex ; blades 1.5-2.5 dm. long, 

 3-6 mm. wide, glabrous beneath, hirsute above toward the base, especially near the base 

 where the hairs are very dense and long : racemes usually 3 or 4, sometimes only 2, spread- 

 ing or ascending, commonly 3-6 cm. long, sometimes shorter : spikelets singly or in pairs, 

 orbicular or nearly so, 2.2-2.5 mm. in diameter, the 2 outer scales 3-nerved, glabrous, the 

 third scale striately I'oughened with conspicuous papillae. 



In wet ground, Florida to Mississippi. Summer and fall. 



