I0 6 GRAMINEAE. 



i. Paspalum mucronatum Muhl. Water Paspalum. (Fig. 227.) 



Paspalum mucronatum Muhl. Cat. 8. 1813. 

 Ceresia fl uitans Ell. Bot. S. C. & Ga. i: 109. 1817. 

 Paspalum fluitans Kunth, Rev. Gram, i: 24. 1829. 



Culms ascending, 6 / -3 long, from a floating or 

 creeping base, branched. Sheaths very loose or in- 

 flated, smooth or scabrous, glabrous or pubescent ; 

 leaves 3 / -i2 / long, 24 '-i' wide, acuminate, scabrous; 

 spikes 20-100, %'-$' long, alternate or whorled, 

 slender ; rachis flat, thin, exceeding the spikelets, 

 long-acuminate, scabrous, its margins nearly en- 

 closing the spikelets ; spikelets in two rows, 

 about y 2 " long, elliptic, pubescent ; outer scales very 

 thin, 2-nerved, the first one usually a little the longer. 



In water, Virginia to southern Illinois and Missouri, 

 south to Florida and Texas. Also in tropical America. 

 Sept. 



2. Paspalum membranaceum Walt. Walter's Paspalum. (Fig. 228.) 



Paspalum membranaceum Walt. Fl. Car. 75. 1788. 

 Not Lam. 1791. 



Paspalum Walterianum Schultes, Mant. 2: 166. 1824. 



Culms erect or ascending, much branched, 

 smooth, creeping at the base. Sheaths a little in- 

 flated, smooth; leaves i^'-^^' long, 2 // -3 // 

 wide, flat, smooth, acute ; spikes 3-7, alternate, 

 about i' long, the lower ones usually included in 

 the upper sheath ; rachis not exceeding the spike- 

 lets, flat, thin, \"-\y^' wide, acute, smooth, 

 many-nerved, its incurved margins partly enclos- 

 ing the spikelets; spikelets about \" long, crowded 

 in 2 rows, oval, obtuse, smooth; outer scales 5- 

 nerved; third scale lenticular, slightly shorter 

 than the outer ones. 



Moist or wet grounds, New Jersey and Delaware to 

 southern Ohio, south to Florida and Texas. Sept. 



3. Paspalum distichum I,. Joint-grass. 

 (Fig. 229.) 



Paspalum distichum ~L,. Amoen. Acad. 5: 391. 1759. 



Culms erect, 6 / -2 tall, extensively creeping at 

 base. Sheaths smooth, sometimes ciliate on the 

 margins, or sparsely pubescent; leaves flat, iy?/~ 

 5' long, i // -2 // wide, acuminate, smooth ; spikes 

 i '-2^' long, in pairs, or occasionally with a third, 

 exserted; rachis flat, >"-i" wide, smooth; spike- 

 lets \]^"-\Y^" 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. 



Virginia to Missouri and California, south to Flor- 

 ida, Texas and Mexico. Also in the West Indies, cen- 

 tral and South America. Aug. -Sept. 



