GRAMINEAE. 73 



1. Paspalum mucronatum Muhl. WATER PASPALUM. (I. F. f. 227.) Culms 

 ascending, 1.5-9 dm. long, from a floating or creeping base, branched. Sheaths 

 very loose or inflated, smooth or scabrous, glabrous or pubescent ; leaves 7.5-30 

 cm. long, 6-25 mm. wide, acuminate, scabrous; spikes 20-100, 1.25-7.5 cm. 

 long, alternate or sometimes approximately whorled, slender ; rachis flat, thin, ex- 

 ceeding the spikelets, long acuminate, scabrous, its margins nearly enclosing the 

 spikelets; spikelets in two rows, about I mm. long, elliptic, pubescent ; outer 

 scales very thin, 2-nerved, the first one usually a little the longer. In water, Va. 

 to southern 111. and Kans., south to Fla. and Tex. Also in tropical America. 

 Sept. (P.fluitans Kunth.) 



2. Paspalum membranaceum Walt. WALTER'S PASPALUM. (I. F. f. 228.) 

 Culms erect or ascending, much branched, smooth, creeping at the base. Sheaths 

 a little inflated, smooth ; leaves 3.75-8.75 cm. long, 4-6 mm. wide ; spikes 3-7, 

 alternate, about 2.5 cm. long, the lower ones usually included in the upper sheath; 

 rachis not exceeding the spikelets, flat, thin, 2-3 mm. wide, acute, smooth, its 

 inrolled margins partly enclosing the spikelets ; spikelets about 2 mm. long, 

 crowded in 2 rows, oval, obtuse, smooth; outer scales 5 -nerved; third scale len- 

 ticular, slightly shorter than the outer ones. Moist or wet grounds, N. J. and Del. 

 to southern Ohio, south to Fla. and Tex. Sept. (P. Walterianum Schultes.) 



3. Paspalum distichum L. JOINT-GRASS. (I. F. f. 229.) Culms erect, 

 1.5-6 dm. tall, extensively creeping at base. Sheaths smooth, sometimes ciliate 

 on the margins, or sparsely pubescent; leaves flat, 3.75-12.5 cm. long, 2-4 mm. 

 wide, acuminate, smooth; spikes 2.5-6.25 cm. long, in pairs, or occasionally with 

 a third, exserted ; rachis flat, 1-2 mm. wide, smooth ; spikelets 2.5-3 mm. long, 

 elliptic, somewhat pubescent or glabrous, acute, nearly sessile in 2 rows ; outer 

 scales 3-5 -nerved, slightly exceeding the acute third one, which is sparingly 

 bearded at the apex. Va. to Mo. and Cal., south to Fla., Tex. and Mex. Also in 

 the West Indies, Central and South America. Aug. -Sept. 



4. Paspalum plenipilum Nash. LONG-HAIRED PASPALUM. Culms 

 tufted, erect, rather slender, 3-8 dm. tall. Sheaths little compressed, very densely 

 pubescent with long spreading white hairs; leaves erect or nearly so, 2.5 dm. or 

 less long, 4-6 mm. wide, densely pubescent on both surfaces with stiff hairs, those, 

 toward the base on the upper surface very long; racemes 2-4, ascending, 3-6 cm. 

 long; spikelets singly arranged, oval, 2.5-2.75 mm. long and about 2 mm. broad, 

 prominently convex on the inner side, the empty scales glabrous, 3 -nerved. In 

 dry places, N. J. Aug. 



5. Paspalum laeve Michx. FIELD PASPALUM. (I. F. f. 234.) Bright green, 

 culms rather stout, erect or ascending, 3-9 dm. tall, glabrous. Sheaths com- 

 pressed, glabrous or somewhat pubescent; leaves 7.5-30 cm. long, 4-8 mm. wide, 

 acuminate, glabrous beneath, hirsute above near the base; spikes 2-6, 3.5-7.5 cm. 

 long, more or less spreading, alternate, about 2-5 cm. apart on the single stout 

 peduncle, pilose in the axils; spikelets 2.53 mm> l n g oval, close, crowded v 



2 rows, glabrous. In moist fields, R. I. to Ky. and Mb., south to Fla. and Tex. 

 Ascends to 1700 ft. in N. C. Aug.-Sept. 



6. Paspalum circulate Nash. ROUND-FLOWERED PASPALUM. Culms 

 erect or nearly so, 3-8 dm. tall. Sheaths compressed, at least the lower ones hir- 

 sute; leaves erect or ascending, 3 dm. or less long, 5 8 mm. wide, glabrous beneath, 

 hirsute above toward the base; racemes usually in pairs, sometimes in 3's, rarely 

 in 4's, 4-9 cm. long; spikelets singly arranged, orbicular, about 3 mm. in dia- 

 meter, the inner side but slightly convex, the empty scales glabrous, very thin, 

 bright green, 3-nerved. In moist or dry fields, N. Y. to N. C. ; also in Mo. July- 

 Sept. 



7. Paspalum glabratum (Engelm.) Mohr. ENGELMANN'S PASPALUM. 

 (I. F. f. 235.) Culms stout, erect, 9-18 dm. tall, from a creeping rootstock, gla- 

 brous. Sheaths glabrous, sometimes glaucous; leaves 24 dm. long, 6-14 mm. 

 wide, acuminate, glabrous beneath, hirsute above; spikes 2-5, on the single stout 

 peduncle, 5-12 cm. long, erect or ascending, bearded in the axils; rachis about 

 2 mm. wide, flat on the back, scabrous on the margins; spikelets 4 mm. long, 

 broadly oval, glabrous, glaucous, singly disposed and crowded in 2 rows; outer 

 scales 5-nerved; third scale striate. Moist places, Del. to Ky. and Kans., south to 

 Fla. and Tex. Sept. (Paspalum Floridanum Michx. in, part.) 



