30 



gent ; panicle depauperate, less than an inch long, the rays single and 

 few flowered. Described from Dr. Chapman's specimens. 



Florida. 



(c) var. major. — Here I could place several variable forms, mostly 

 smooth, with stouter culms, a more open, less dense panicle, with 

 fewer and 'stouter branches (sometimes reflexed), and fewer and larger 

 spikelets. 



34. P. laxiflorum, Lam. — Culms erect, weak, G to 18 inches high, rarely 

 branched, smooth below the panicle ; leaves linear or lanceolate-linear, 

 3 to 7 inches long, 3 to 4 lines wide, mostly radical, the 2 or 3 of the 

 culm little shorter, acuminate, nearly smooth except on the ciliate mar- 

 gins, pale green or yellowish-green; sheaths mostly shorter than the 

 leaves, sparsely and retrorsely villose ; ligule a ring of soft, white 

 hairs, panicle capillary, 2 or 3 inches long, branches sparingly divided 

 from the base, mostly single? alternate and few flowered, spreading; the 

 rhachis and branches sparsely long-hairy; spikelets long-pedicelled, 1 

 line long, oval, or elliptical, obtuse, strigosely pubescent, lower empty 

 glume ovate, one nerved, one-quarter as long as the spikelet; second 

 and third glumes seven to nine nerved ; fertile flower as long as the 

 spikelet, acutish. In sandy woods. 



Yar. pubescens. — Culm rather stouter, and pubescent, 12 to 15 inches 

 high ; leaves hairy, shorter, lanceolate, the lower 2 to 2£ inches long, 3 

 to 5 lines wide, the upper about 1 inch, upper sheath elongated; pani- 

 cle 2 to 3J inches long, the branches and spikelets more numerous, and 

 spikelets smaller; lowest glume roundish ovate, one-third as long as 

 the spikelets; second and third glumes five to seven nerved. Closely ap- 

 proaches P. nitidum, and is perhaps the P. nitidum, var. ciliatum, Torr. 



35. P. dichotomum, Linn. — Culm 10 to 30 inches high ; at first mostly 

 simple, smooth, or pubescent, bearing a more or less exserted, spread- 

 ing, compound panicle, 1 to 4 inches long, and lanceolate, flat leaves; 

 those of the culm larger above, 3 to 4 inches long; those at the root 

 tufted, usually ovate-lanceolate, short, and thick ; the culms commonly 

 branching later in the season, the branches often clustered, and bearing 

 smaller, mostly included panicles ; spikelets about 1 line long (two- 

 thirds of a line to 1 line), oblong-obovate, pubescent or downy, lower 

 glume one -third as long as the spikelet. 



(a) Variety barbulatum. — With the nodes barbed, and with the 

 sheaths smooth or pubescent. 



(b) Variety viride. — Smooth all over, leaves light green and narrower. 



(c) Var. divaricatum. — Eiect, 6 to 9 inches high, slender, smooth, very 

 much branched above the base, caespitose, the radical leaves very short 

 and tufted, those of the culm and branches very narrowly linear or in- 

 volute, acuminate, about 1 inch long, divaricate, the numerous panicles 

 small, racemose, few flowered ; the spikelets on alternate, filiform ped- 

 icels one-half inch to 1 inch long ; spikelets three-fourths of a line long, 

 oval-oblong, smooth, the lower glume one-third as long as the spikelet; 

 second glume one-third shorter than the spikelet, five-nerved ; third 



