POACEAE 67 
fourth scale twice bent, 2-3 cm. long, closely spiral to the second bend, thence loosely 
twisted, the column very much exserted ; pedicel from 3 as long as the spikelet to nearly 
equalling it. [Sorghum nutans Chapm. ] E x 
In dry soil, South Carolina and Tennessee to Florida and Mississippi. Fall. 
3. Sorghastrum secándum ( Ell.) Nash.. Stems 8-14 dm. tall : leaf-sheaths smooth 
and glabrous ; blades 6 dm. long or less, 7 mm. wide or less, smooth beneath, rough above, 
often involute: panicle 2-4 dm. long, one-sided, its branches erect or nearly so, rarely 
exceeding 4 em. in length, usually shorter than the internodes of the axis, the ultimate 
divisions much curved, making the spikelets reflexed: spikelet 6-8 mm. long, lanceolate, 
the 2 outer scales golden brown and indurated at maturity, the first one pubescent with 
long erect hairs, the awn of the fourth scale twice bent, 2.5-3 cm. long, closely spiral to the 
second bend, thence loosely twisted, the column very much exserted ; pedicel from 3-3 as 
long as the spikelet. [Sorghum secundum ( Ell.) Chapm. ] 
In dry sandy soil, Georgia and Florida. Fall. WILD Oats. 
13. VETIVERIA Thouars. 
Tall grasses with simple stems, narrow leaf-blades and terminal panicles with the 
branches usually much articulated and disposed in dense whorls. Spikelets in pairs, 
narrow, acute, of 4 scales, the one sessile and perfect, the other pedicellate and staminate. 
Sessile spikelets usually somewhat laterally compressed, the first scale coriaceous or char- 
taceous, the margin inflexed or involute, the second awned or awnless, the third and fourth 
scales hyaline, the latter entire or shortly 2-toothed, mucronate or awned from between the 
teeth. Pedicellate spikelets usually awnless, rarely awned. Stames 3. Styles distinct. 
Stigmas plumose. 
l. Vetiveria zizanioides (L.) Nash. Stems 2 m. tall or more: sheaths smooth and 
glabrous ; blades 9 dm. long or less, 4-10 mm. wide: panicle 2-3 dm. long, its slender as- 
cending or nearly erect branches in dense whorls and readily disarticulating at the nodes : 
sessile spikelet about 4 mm. long, about as long as the internode, the first scale minutely 
tuberculate-roughened, 2-keeled, the keels muricate, the second scale 1-keeled, the keel 
muricate, the fourth scale awnless or short-awned, the awn not exserted beyond the 2 outer 
scales ; pedicellate spikelet about as long as or a little shorter than the sessile, the 2 outer 
scales sparingly muricate. 
Cultivated and escaping into fields in Louisiana. Fall. 
14. RHAPHIS Lour. 
Perennial or rarely annual grasses, with narrow leaf-blades and terminal panicles, 
whose branches usually bear clusters of 3 spikelets, or very rarely more, at the end, one 
spikelet sessile and perfect, the other 2 staminate or sterile and pedicellate. Sessile spike- 
lets usually somewhat laterally compressed, of 4 scales, the first scale broadly involute, the 
second somewhat distinctly keeled, and usually awned, the third and fourth scales hyaline, 
the latter usually awned.  Pedicellate spikelets dorsally compressed, awnless or awned. 
Stamens 3. Styles distinct. Stigmas plumose. 
1. Rhaphis pauciflórus (Chapm.) Nash. Annual. Stems 6-12 dm. tall, simple or 
somewhat branched : leaf-blades 2 dm. long or less, 2-10 mm. wide, papillose-hirsute 
above: panicle 2-3 dm. long, its branches erect or ascending, slender, the lower in whorls 
of 2-5, rarely divided, the longer, exclusive of the spikelets and awn, 5-8 cm. long: ses- 
sile spikelet about 15 mm. long, including the 6-7 mm. long and densely p callus, 
cylindric or slightly zen d compressed, the first and second scales dark brown, shining 
and coriaceous at maturity, hispidulous at the apex, the fourth scale emitting a flexuous 
more or less contorted usually geniculate awn 14-16 cm. long; pedicellate spikelet 10-12 
mm. long, on slender pedicels about reaching the apex of the sessile spikelet, empty or 
containing a staminate flower. [Sorghum pauciflorum Chapm. 
In dry sandy soil, eastern and peninsular Florida. Alsoin Cuba. Fall. 
15. HETEROPOGON Pers. 
Annual or perennial grasses, sometimes tall, with narrow leaf-blades and compressed 
sheaths, and terminal solitary dense racemes. Spikelets 1-flowered, in pairs at the rachis- 
nodes, one sessile and fertile, the other pedicellate, containing a staminate flower, or empty. 
Scales of the sessile spikelets 4, the outermost empty, firm, convolute, awnless, the second 
also empty, thinner, keeled, the third scale very thinly hyaline, likewise empty, the 
