616 CLXL GRAMINEiE. Uniola. 



spikelets terete, linear, purplish, about 5-flowered; fls. obtuse, indistinctly 5- 

 veined. — % Salt marshes, Ms., Bigclow. June. 



18. P. AaLATicA. /?. Americana. Torr, (P. aquatica. Ph.) 



Smooth ; st. stout, leaty, 4 — 5f high ; lis. broad-linear, flat, thin ; panicle 

 erect, diffuse, branches at length spreading, flexuous, 3 — 5 together, in half 

 whorls ; spikelets linear, purple, with G — 8 ovate-obtuse flowers. — % Wet mea- 

 dows, Free Stales and Can. A very large, handsome poa. Aug. 



19. P. DEN'TATA. Torr. 



Smooth ; 5^. erect, round, 3f high ; Ivs. flat, linear, 10 — 16' long, glaucous 

 beneath; slip, elongated; panicle large, loose, lew-flowered, branches capillary, 

 spreading ; spi/iclcts lanceolate, about 5-flowered ; lower glume 3-veined ; loiuer 

 paka 5-\xined, 5-toothed at the apex when old. — % Swamps, Mass., N. H. ! to 

 Penn. Not very common. June, July. 



20. P. FAscicuLATA. Torr. 



Very smooth ; st. firm and leafy, oblique, round, branched at base, 1 — 2f 

 high; lis. flat, lance-linear ; panicle spreading, branches fasciculate, crowded, 

 straight ; spikelets oblong, somewhat racemed, sessile, crowded, about 3-flow- 

 ered; glumes minute, unequal. — Tj. Salt marshes, N. Y, 



21. P. PECTiNACEA. Michx. (P. pllosa. Muhl. P. tenella. Ph.) 



St. coBspltose, oblique, geniculate at base, 8 — 12' high ; lis. flat, smooth, 

 pilose at base, 5- veined, 2 — 4' long; sheatJis bearded at the throat; panicle large, 

 loose, capillary, purplish, hairy in the axils, branches subverticillate ; spikelets 

 linear, with 5 — 9 acute flowers ; upper palea persistent on the rachis which thus 

 is made finally to appear pectinate. — In sandy fields, Mid. and S. States. 

 July, Aug. 



22. P. REPTANS. 



J* 9; 5^ branched, creeping, rooting at the joints, 6 — 12' long; lis. subu- 

 late, flat, 2 — 3' long; sheaths open, pilose on the margin and throat: panicle 

 1 — 2' long, branches short, simple, in fascicles, few-flowered ; spikekts linear- 

 lanceolate, with 12 — 20 acuminate flowers. — Swamps, N. Y. to Ky. ! Jl , Aug. 



23. P. Eragrostis. (P. obtusa. Niitt. Briza eragrostis. Muhl.) 



St. oblique or decumbent, geniculate, 1 — 2f long ; Irs. lanceolate, attenu- 

 ate at end, scabrous on the margin and above ; .sheaths pilose at the throat ; slip. 

 short, bearded ; panicle expanding, branches subdivided, flexuous, subpilose in 

 the axils ; spikelets ovate-oblong, 12 — 20-flowered ; glumes nearly equal. — A 

 beautiful grass, introduced into fields and roadside's, N, Eng. to 111. ! It has a 

 strong, peculiar odor. Aug. <\ 



42. BRIZA. 



Gr. Ppi^u), to nod, or hang down ; alluding to the penduloiis spikelets. 



Spikelets cordate-ovate. 6 — 9-flowered ; glumes 2, shorter than the 

 lower flowers ; paleas ventricose, lower one cordate at base, embracing 

 the upper which is suborbicular and much shorter ; carjopsis beaked. 

 B. media. 



St. naked above, 1 — 2f high; Ivs. flat, smooth, lance-linear; slip, short, 

 obtuse ; panicle erect, few-flowered, branches wide-spreading, capillary, pur- 

 plish, bearing the ovate or cordate, tumid, pendant and tremulous spikelets at 

 the ends, these are about 7-flowered, greenish-purple; pakce veinless. — Tl-Natu- 

 ralized in the vicinity of Boston, Bigelow. May. 



43. UNIOLA. 



Lat. unus, one ; on account of the aggregation of many flowers into one spikelet. 



Spikelets compressed, 3 — 20-flowered ; lower flower abortive ; 



glumes 2, shorter than the lower flower ; lower paleaa boat-shaped at 



the end, truncate and mucronate between the lobes, upper subulate, 



somewhat bifid; scales emarginate ; caryopsis with 2 horns. 



1. (J. LATiFOLiA. Michx. Broad-lcaved Uniola. 



St. 2 — 4f high, smooth, subsimple ; Irs. 8 — 18' by G — 12", lance-linear, 



