570 GRAMINE^:. (GRASS FAMILY.) 



lindrical (2' -4' long), somewhat interrupted at the base ; glumes short-pointed, 

 rather narrowly keeled, J longer than the ovate hairy flower. South Carolina, 

 and westward, (l) Leaves not glaucous, 4' - 10' long. 



47. PASPALUM, L. 



Spikelets spiked or somewhat racemed, apparently 1 -flowered, awnless, borne 

 in 1 - 4 rows on one side of the flattened or triangular jointless rachis. Glumes 

 2, membranaceous, nearly equal. Paleae 2, ovate or roundish, coriaceous ; the 

 lower one larger, concave, and partly enclosing the flattened upper one. Sta- 

 mens 3. Grain included in the indurated paleae. Such is the apparent structure 

 of the spikelet, but theoretically it is 2-flowered, as in Panicum, with the lower 

 glume and upper palea of the lower flower undeveloped. 



* Spikes racemed: spinets partly enclosed by the recurved margins of the broadly 



'winged membranaceous rachis. 



1. P. fluitans, Kunth. Spikes very numerous ; spikelets in two rows, mi- 

 nute (I" long), oblong, pubescent ; glumes pointed ; culm branching, ascending 

 from a creeping or floating base; leaves flat, broadly linear (4" -8" wide). 

 (Ceresia fluitans, Ell.) River-swamps, Florida, and northward. Sept. and 

 Oct. (g -Culms smooth, l-3 long. 



2. P. Walter!, Schultes. Smooth ; spikes 3-7, the lowest ones included 

 in the sheath of the uppermost leaf; spikelets in two rows, ovate, smooth ; glumes 

 obtuse, 5-nerved. (P. vaginatum, Ell.) Low cultivated grounds, Florida to 

 North Carolina, and westward. July and Aug. Culms decumbent, creeping, 

 l-3 long. Leaves linear, short. 



* * Spikes mostly by pairs, divaricate : spikelets ovate-lanceolate, acute, 2-rowed on 



the slender wingless rachis : glumes smooth, longer than the palece. 



3. P. Digitaria, Poir. Peduncles elongated, lateral and terminal, often 

 2-3 together from the upper sheath; spikes (3'-4' long) filiform, spreading 

 horizontally; glumes even, 7-nerved, J longer than the obtuse perfect flower; 

 culms ascending from a creeping and branching base ; leaves lanceolate, obtuse, 

 flat, mostly fringed on the margins, the sheaths compressed. (Milium paspa- 

 lodes, Ell.) Open swamps, Florida to North Carolina, and westward. July- 

 Sept. ty Culms 1 - 2 high. 



4. P. vaginatum, Swartz. Peduncles single, terminal, spikes (rarely 3 or 

 4) short (!'- 1^' long), erect or horizontal; glumes rugose, 5-nerved, rather longer 

 than the acute flower ; culms diffusely creeping, short-jointed ; the flowering 

 branches (4'- 10' long) erect; leaves (l'-3'long) subulate-convolute, their dilated 

 imbricated sheaths persistent. (P. furcatum, Fluegge.) Saline swamps, West 

 Florida, and southward. Aug. and Sept. 1J. Culms 2 * 4 long. Sheaths 

 compressed, bearded at the throat. 



* * * Spikes solitary, or few and racemose: spikelets ovate or roundish, in 2-4 



rows: rachis mostly flattened andflexuous: glumes and palece nearly equal. 



5. P. distichum, L. Spikes 2, rarely 3 or 4, spreading (!'-!' long); 

 spikelets in 2 rows, single, ovate, acute, as wide as the straight rachis ; glumes 



