POACEAE. 



15 



7. Paspalum vaginatum Sw. 



SHEATHED PASPALUM. (Fig. 14.) Culms 

 8 '-2 tall, from a long stout rootstock; 

 leaf-sheaths compressed, keeled, usually 

 crowded and overlapping, at least at the 

 base and on the innovations, glabrous; 

 blades folded, or involute when dry, 6' 

 long or less, l"-2" wide, glabrous, or 

 sparingly hairy; racemes terminal, usu- 

 ally a pair, rarely more or but a single 

 one, erect or ascending, 2 '-3' long: spike- 

 lets singly disposed, ovate-lanceolate, 

 acute, li"-2" long, the 2 outer scales gla- 

 brous, thin, the first scale 4-nerved, the 

 lateral nerves approximate at the margin, 

 the midnerve suppressed, the second scale 

 5-nerved, the lateral nerves rather near 

 together, the third scale glabrous at the 

 apex or with 2 or 3 hairs. 



Frequent in brackish marshes. Native. 

 Southern United States and West Indies. 

 Its seeds probably transported by birds. 

 Flowers in summer and autumn. 



Paspalum filiforme Sw., a West Indian grass recorded as Bermudian by 

 Jones, Eeade and by Lefroy, as wire-grass, and admitted by Hemsley, has not 

 been found by recent collectors. (See P. caespitosum.) 



4. PASTICUM L. 



Annuals or perennials, various in habit, with open or contracted panicles 

 or 1-sided spike-like racemes. Spikelets 1-2-flowered, when 2-flowered the 

 lower one staminate only. Scales 4, the 3 lower membranous, empty, or the 

 third with a staminate flower, varying in the same species ; the inner or fourth 

 scale chartaceous, shining, enclosing a palet of similar texture and a perfect 

 flower. Awns none. Stamens 3. Styles distinct. Stigmas plumose. Grain 

 free, enclosed in the hardened fruiting scale and palet. [Old Latin name for 

 some grass, probably the cultivated Sorghum, referring to its panicle, taken 

 from Pliny.] About 500 species, in temperate and tropical regions. Type 

 species: Panicum miliaceum L. 



Spikelets in pairs in one-sided spike-like racemes. 

 Glabrous. 



Pubescent, at least at the nodei. 

 Spikelets panicled. 



Fourth scale of the spikelet smooth. 

 Annual grasses. 



Leaf-sheaths pubescent. 

 Leaf-sheaths glabrous. 

 Tall perennial grass. 

 Fourth scale transversely rugose ; tall grass. 



1. P. germinatum. 



2. P. barbinode. 



3. P. capillare. 



4. P. dichotomiflorum. 



5. P. virgatum. 



6. P. maximum. 



