84 NORTH AMERICAN FLORA [VoLumE 17 
Inflorescence decompound ; or if compound, the racemes 
with a long naked base, the spikelets sometimes 
reduced to a group of 3 at the end. 
Spikelets dorsally compressed ; inflorescence decom- 
pound. 
Pedicellate spikelets wanting. 25. SORGHASTRUM. 
Pedicellate spikelets present. 26. HOLcus. 
Spikelets laterally compressed ; inflorescence com- 
pound, the racemes with a long naked base. 
Racemes of many internodes, numerous in whorls 
at the nodes of the panicle axis; spikelets awn- 
less or with imperfect awns. 27, VETIVERIA. 
Racemes of 1 internode, rarely of 2 internodes, in : 
2’s-4’s at the nodes of the panicle axis; spikelets ‘ 
with long perfect awns, 8. CHRYSOPOGON. 
A false whorl of 4 or more staminate or empty spikelets at the 
base of each raceme. 29. THEMEDA. 
5. STEGOSIA Lour. Fl. Cochinch. 51. 1790. 
Tall annual grasses, with flat leaf-blades, and false spikes borne singly at the apex of 
the stem and itsbranches. Rachis of the spikes readily disarticulating, the separated inter- 
nodes furnished with a pit or excavation at the summit, the pedicels grown to the rachis, 
the upper part of the spikes narrowed into a long tail, consisting of imperfect spikelets. 
Spikelets 1- or 2-Howered, in pairs, both appearing sessile from the attachment of the pedicel 
to the rachis. Sessile spikelet with the first scale coriaceous or cartilaginous, convex, with 
narrowly inflexed margins, closing the cavity in the rachis; second scale chartaceous or 
subcoriaceous, keeled ; third scale hyaline, empty, or enclosing a palet and sometimes also 
a staminate flower; fourth scale hyaline, enclosing perfect flower. Stamens 3. Styles 
short, not exserted. 
Type species, Stegosia cochinchinensis Lour. 
1. Stegosia exaltata (1,.f.) Nash. 
Rotiboellia exaliaia I,.f. Suppl. 114. 1781. 
Stegosia cochinchinensis Lour. Fl. Cochinch. 51. 1790. 
Rottboellia setosa Presl, Relig. Haenk. 1: 329. 1830. 
Rotiboellia arundinacea Hochst.; A. Rich. Tent. Fl. Abyss. 2: 444. 1851. 
Rotiboellia denudata Steud. Syn. Gram. 362. 1855. 
Manisuris exaliata Kuntze, Rev. Gen. 779, 1891. 
Stems up to 3m. tall, branched; leaf-sheaths, at least the lower ones, papillose-his- 
pid; blades linear-lanceolate, up to 6 dm. long and 3 cm. wide, the lower surface smooth, 
the upper rough and sometimes hairy; spikes up to 1.5 dm. long and 5 mm. in diameter ; 
sessile spikelet 1- or 2-flowered, 5-7 mm. long, including the basal callus, the first scale ob- 
long-elliptic, obtusely acute; pedicellate spikelet 1- or 2-flowered, or sometimes reduced to 
a single scale. 
TYPE LOCALITY: Indies. 
DISTRIBUTION: Introduced into Jamaica, Haiti, and Grenada to Trinidad. Widely spread in 
the tropics of the Old World. 
ILLUSTRATION: Roxb. Pl. Corom. pl. 157. 
6. COELORACHIS Brongn. in Duperrey, Voy. Coq. Bot. 
Phan. 64. 1831. 
Lasiurus Boiss, Diagn. Pl. Orient. II. 4: 145. 1859. 
Apogonia Fourn. Mex. Pl. Gram. 63. 1881. 
Perennial, often tall, grasses, varying in habit, with flat or involute leaf-blades, and 
cylindric racemes which are borne singly at the apex of the stem or its branches. Rachis 
of the racemes readily disarticulating, the internodes, when separated, furnished with a pit 
or excavation at the apex, the pedicels free from therachis. Spikelets 1- or 2-flowered, in 
pairs, the pedicellate similar in shape to the sessile or reduced to scales. First scale of the 
sessile spikelet coriaceous or cartilaginous, convex, with narrow inflexed margins, entirely 
closing the cavity in the rachis; second scale chartaceous or subcoriaceous, keeled ; third 
scale hyaline or membranous, empty, or enclosing a palet and more rarely also a staminate 
flower; fourth-scale hyaline, enclosing a perfect flower. Scales of the pedicellate spikelet 
