18 POACEAE. 



19. P. robbarbulatiun Scribn. & Mer. Stems 6-12 dm. tall: leaves 6 or 7; 

 blades spreading, 3-8 em. long, 3-10 mm. wide, the lowermost pubescent on 

 both surfaces: panicle 6-10 dm. long, orate: spikelets 2-2.5 mm. long and 

 about 1 mm. wide, elliptic. Hammocks and pinelands. (Bah., Cuba.) 



20. P. ensifolium Baldw. Stems 1-3 dm. tall: leaves 2 or 3; blades widely 

 spreading, lanceolate, usually less than 2 cm. long, 1-3 mm. wide, densely 

 puberulent on the lower surface, the basal blades markedly larger and more 

 erect: panicle small, ovate, 1-2 cm. long: spikelets about 1.3 mm. long and 

 about 0.6 mm. wide, elliptic. Hammocks. 



21. P. albomarginatum Nash. Glabrous: stems 2-4 dm. tall, the upper part of 

 the stem naked: leaves usually 2; blades erect, thick, stiff, lanceolate, with a 

 prominent wide thickened white margin, usually 1.5-4 cm. long, 27 mm. wide: 

 panicle 2-4 cm. long, broadly ovate: spikelets elliptic, about 1.3 mm. long, 

 and 0.7 mm. wide. Pinelands. (Cuba.) 



22. P. trifolimn Nash. Stems 2-4 dm. tall: leaves 3, rarely 4, the uppermost 

 one much above the middle of the stem and generally but a little below the 

 panicle; blades erect or nearly so, firm, lanceolate, the margins thickened and 

 cartilaginous, 1.5-6 cm. long, 1.5-5 mm. wide: panicle 2.5-6 cm. long, broadly 

 ovoid: spikelets 1.5 mm. long and about 0.7 mm. wide, ellipsoid. Pinelands. 



23. P. caerulescens Hack. Glabrous: stems erect, 7-11 dm. tall: leaves 6-8; 

 blades erect, firm, 4-11 cm. long, 4-8 mm. wide, lanceolate: panicle 9-13 cm. 

 long, oblong, dense, 2-4 cm. wide: spikelets 1.3 mm. long and .about 0.8 mm. 

 wide, oval. Pinelands. (Bah., Cuba.) 



24. P. erectifolium Nash. Stems 5-7 dm. tall: leaves usually 5-7; blades erect, 

 firm, ciliate on the margins toward the base, lanceolate, acuminate, 5-10 cm. 

 long, 5-13 mm. wide: panicle elliptic, 8-12 cm. wide: spikelets numerous, 0.6- 

 0.8 mm. wide, elliptic to oval. Pinelands. (Cuba.) 



25. P. ciliiferum Nash. Stems 2-5 dm. tall: leaves usually 3; sheaths densely 

 hirsute with long ascending hairs; blades erect or ascending, lanceolate, the 

 lower surface strongly strigose, the primary ones 3-8 cm. long, 4-10 mm. 

 primary panicle ample, 6-11 cm. long, broadly oval: spikelets about 2.75 mm. 

 long and 1-1.2 mm. wide, elliptic. Pinelands. 



26. P. pseudopubescens Nash. Stems 2-4 dm. tall: leaves usually 3: blades 

 erect, rather firm, lanceolate, 4-10 cm. long, 3-11 mm. wide: panicle 5-9 cm. 

 long, broadly ovoid: spikelets 2.25-2.4 mm. long and 1-1.2 mm. wide. Pine- 

 lands. 



27. P. epilifolium Nash. Stems 2-3.5 dm. tall: leaves 2 or 3; sheaths ciliate 

 on both margins with long slender hairs; blades linear-lanceolate, 4-7 cm. long, 

 5-7 mm. wide, minutely pubescent on the upper surface between the nerves: 

 panicle 5-7 cm. long, ovate, obtusely apiculate. Hammocks. 



28. P. equilaterale Scribn. Stems 4-8 dm. tall: leaves 4 or 5; blades elongate, 

 8-18 em. long, 7-15 mm. wide: panicle 7-9 cm. long, broadly ovate: spikelets 

 about 3.5 mm. long and about 1.3 mm. wide, elliptic, acutish. Pinelands. 



29. P. manatense Naxh. Stems 2-4 dm. long: leaf -blades erect or nearly HO, 

 lanceolate, 3-9 cm. long, 7-15 mm. wide: panicle 4-6 cm. long: spikelets ellip 

 tic, about 3 mm. long and 1.3 mm. wide, strongly pubescent with spreading 

 hairs. Hammocks. 



SO. P. commutatum R. ft 8. Steins 3-6 dm. tall : leaves 3 or 4 ; blades ciliate 

 on the margin, 5-12 cm. long, 1-2 cm. wide, ovate-lanceolate: panicle 5-10 cm. 

 long, broadly ovoid: spikelets 2.5-3 mm. long and about 1 mm. wide, elliptic. 

 obttue or acutisb. pubescent. Pinelands. 



16. 8TEINCHI8MA Raf. Erect tufted plants with loose open panicles. 

 Spiketets with the 3 outer scales membranous, the third scale bearing in its 



