310 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



colored, drying brown, oval, about 2.5 mm. long, strongly plano-convex, the 

 sterile lemma at maturity finely undulate inside the slightly raised margin; 

 fruit dark brown, shining. 



Open slopes, banks, and savannas, mostly moist soil, southeastern United 

 States to Argentina; throughout the West Indies except Bermuda and the 

 Bahamas. Originally described from Georgia and Florida; Paspalum undula- 

 tum described from Porto Rico, and P. antillense from Guadeloupe. 



15. Paspalum olivaceum sp. nov. 



A leafy annual, olivaceous wjien dry; culms glabrous, slightly fleshy, com- 

 pressed-striate when dry, 40 to i30 cm. long, ascending from a decumbent base, 

 often rooming at the lower nodes, finally bearing simple floriferous branches; 

 sheaths loose, thin, compressed, glabrous ; ligule membranaceous, erose, 1.5 to 

 2 mm. long ; blades lax, ergct, at least at the- base, flat, or folded at base, com- 

 monly 10 to 15 cm. long, .^ to 10 mm. wide, usually pilose on the upper surface 

 at base, otherwise glabrous ; panicle short-exserted from the bladeless upper 

 sheath, the slender subflexuous axis 4 to 7 mm. long ; racemes 3 to 7, arcuate- 

 spreading, 2 to -3t5 cm. long, the rachis scarcely 1 mm. wide, a few long hairs 

 at the base; spikelets mostly in pairs, 2 mm. long, 1.5 mm. wide, obovate, 

 strongly convex on the back; glume and sterile lemma equal, 5-nerved, thin 

 and commonly torn, glabrous or the glume obscurely strigose, the lemma often 

 minutely wrinkled inside the slightly raised margin; fruit dark brown, shin- 

 ing, obovate-hemispherical. 



Type in U. S. National Herbarium, no. 559837, collected in the island of 

 Guadeloupe, September 23, 1897, by Pere Duss (no. 3915). 



Paspalum olivaceum is one of the group of brown-fruited annuals to which 

 P. boscianum belongs. Because of its wrinkled sterile lemma it looks like a 

 small lax-leaved P. plicatulum,, from which species it differs in its branching 

 culms and smaller spikelets and in being an annual. No habitat is given on 

 the labels of the specimens, but the species is, probably, like^its allies, found 

 along ditches and in wet clay ground. Guadeloupe, Martinique, and the 

 Guianas. 



16. Paspalum wrightii sp. nov. 



A glabrous perennial, the culms 1.5 meters or more long, simple, decumbent or 

 floating at the base, with rootlets at the distant nodes, lush, with loose over- 

 lapping sheaths, the upper sheaths close, elongate; ligule membranaceous, 1 

 mm. long; blades suberect, rather firm, 20 to 40 cm. long, about 5 mm. wide 

 (the uppermost greatly reduced), involute toward the summit, scabrous on, 

 the margins and bearing a tuft of long hairs just back of the ligule ; racemes 

 5 or 6, ascending, 4 to 6 cm. long, the common axis slender, 8 to 10 cm. long, 

 not hairy in the axils or with one or two hairs only ; rachis 1.5 mm. wide, 

 glabrous, the margin minutely scabrous ; spikelets in pairs, closely imbricate, 

 2.2 to 2.5 mm. long, about 1.4 mm. wide, elliptic to slightly obovate, glabrous, 

 the glume and sterile lemma equal, thin, slightly and irregularly wrinkled, 

 3-nerved or with an additional obscure pair near the margin; fruit about 2.2 

 mm. long, 1.2 mm. wide, elliptic, chestnut-brown, the rolled margins, of the 

 lemma pale. 



Type in the U. S. National Herbarium, no. 865562, collected in Cuba by 

 Charles Wright (no. 3843). 



Apparently an aquatic or semiaquatic and probably allied to Paspalum plica- 

 tulum. Known only from the type collection, on which is given no date and 

 no locality other than Cuba. The floating habit is inferred from the texture 

 of the lower part of the culm and its loose slightly inflated sheaths. In the 



