GRAMIXE.E. (grass FAMILY.) 583 



with leaves 2° loug. P. amplecteus, CItapm. in Bot. Gazette, a slender form, 

 with uarrow (1" wide) setaceously pointed leaves.) — Wet ground, common. 



14. P. hians, Ell- Paniule 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 flow'ers neutral, longer than tlie 

 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. 



•1- -(- Root perennial. 



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

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

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

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

 minute! V bearded floret. — Bogs and marshes, Florida to North Carolina. 



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

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

 or iu clusters, ovate-lanceolate, acute, \^" long; glumes laterally compressed 

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

 one ttiird longer than the floret. — Low ground, common. 



17. P. stenod.es, Griseb. Culms simple or branched, 2° -3° high; 

 leaves narrow-linear, erect ; ])anicle mostly terminal, small and spike-like, or 

 larger and spreading; spikelets as in the preceding, about 1" long, more or 

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

 Florida, and westward, near the coast. 



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

 12'- 14' long, 1' or more wide; panicle nearly simple, the straight spreading 

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

 spikelets iu short 3 - 5-flowered l-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- 

 wliat 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. 



-i- Culms tall, simple: panicle 1° or more long. 



20. P. virgatum, 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"loug; glumes acuminate, the upper 7-nerved, one third 

 longer than the lowest, and the obtu.se floret ; sterile flower triaudrous. — 

 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. 



