GRAMINE^E. (GRASS FAMILY.) 583 



with leaves 2 long. P. amplectens, Chapm. in Bot. Gazette, a slender form, 

 with narrow (1" wide) setaeeously pointed leaves.) Wet ground, common. 



14. P. hians, Ell. Panicle small, the few scattered spreading branches 

 naked below; spikelets in small dense clusters, ovate; upper glume 5-nerved, 

 3-4 times longer than the lower ; sterile flowers neutral, longer than the 

 floret; palet rigid, obovate, involute, gaping at the apex; culms slender (6'- 

 18' high); leaves linear, smooth. Low grounds in fields and along roads, 

 Florida to North Carolina. 



-t- <- Root perennial. 



15. P. agrostoides, Spreng. Culms stout, 2 -4 high, compressed, 

 like the sheaths of the long linear leaves ; panicles lateral and terminal, 4'- 8' 

 long, closely branched, the small (1" long) purplish spikelets crowded on the 

 short spreading branches ; second glume twice as long as the first, and the 

 minutely bearded floret. Bogs and marshes, Florida to North Carolina. 



16. P. anceps, Michx. Culms erect, 2 -3 high, flat, like the sheaths 

 of the long broadly linear spreading leaves ; spikelets mostly crowded, singly 

 or in clusters, ovate-lanceolate, acute, 1$" long; glumes laterally compressed 

 at the top, soon spreading, the second 7-nerved, twice as long as the first, and 

 one third longer than the floret. Low ground, common. 



17. P. stenodes, Griseb. Culms simple or branched, 2 -3 high; 

 leaves narrow-linear, erect ; panicle mostly terminal, small and spike-like, or 

 larger and spreading; spikelets as in the preceding, about \" long, more or 

 less crowded; glumes 5-nerved. (P. anceps, var., Flora.) Low ground, 

 Florida, and westward, near the coast. 



18. P. gymnocarpum, Ell. Culms stout, 2 - 4 high ; leaves smooth, 

 12'- 14' long, I' or more wide; panicle nearly simple, the straight spreading 

 branches (4' -6' long) clustered or whorled, bearing the lanceolate acuminate 

 spikelets in short 3 - 5-flowered 1-sided racemes; glumes open, the first and 

 third equal, the second longer, 5-nerved, more than twice as long as the floret. 

 River banks, Georgia, Florida, and westward. 



19. P. repens, L. Culms simple, erect from a creeping base, l-2 

 high; leaves narrow, involute, 2' - 4' long, rigid; panicle 2' -4' long, some- 

 what corymbose ; spikelets single, oval, 1 " long ; upper glumes acute, 7-nerved, 

 as long as the floret. Along the coast, Florida, and westward. 



* * * Panicle mostly decompound : spikelets shorter than their pedicels. 

 t Culms tall, simple: panicle 1 or more long. 



20. P. vil'gatum, L. Culms 2 -4 high; leaves broadly linear, flat, 1 

 or more long; branches of the large spreading panicle whorled or clustered ; 

 spikelets ovate, l"long; glumes acuminate, the upper 7-nerved, one third 

 longer than the lowest, and the obtuse floret ; sterile flower triandrous. 

 Open woods, common. 



21. P. amarum, Ell. Glaucous; culms stout, 3 - 6 long ; leaves long 

 and rigid, soon convolute; panicle 1- 2 long, the branches erect; spikelets 

 like those of the preceding, but larger. Drifting sands along the coast, Flor- 

 ida to North Carolina. 



