94 NORTH AMERICAN FLORA LVoLUME 17 
many-jointed, the rachis fragile and readily disarticulating. Spikelets in pairs, one sessile, 
the other pedicellate. Sessile spikelet 2-flowered, the lower flower usually staminate, the 
upper perfect; first scale chartaceous or coriaceous, awnless, flat or somewhat depressed on 
the back; second scale sometimes awned ; third awnless and enclosing a staminate or very 
rarely a perfect flower; fourth scale hyaline or membranous, usually bifid and bearing a 
perfect awn from the sinus, the awn rarely imperfect or wanting. Pedicellate spikelets vary- 
ing in sex. Stamens 3. Stigmas oblong, usually equaling the styles, exserted above the 
middle of the spikelet. 
Type species, [schaemum muticum ly. 
Racemes numerous at the apex of the stem and its branches; first scale of the 
spikelet not rugose. 1. L. latifolium. 
Racemes in pairs at the apex of the stem and its branches; first scale of the spike- 
let transversely rugose. 2. [. rugosum. 
1. Ischaemum latifolium (Spreng.) Kunth, Rev. Gram. 371. 1830. 
Andropogon latifolius Spreng. Syst. 1: 286. 1825. 
Spodiopogon latifolius Nees, Agrost. Bras. 360. 1829. 
Andropogon diatherus Steud. Syn. Gram. 378. 1855. 
Ischaemopogon latifolius Griseb. F1. Brit. W. Ind. 560. 1864. 
Ischaemum latifolium minus Fourn. Mex. Pl. Gram. 55. 1881. 
A tall grass with short extravaginal innovations. Stems decumbent at the base, ascend- 
ing, up to 1 m. tall, glabrous, bearing leafy branches below, flower-bearing ones above; 
leaf-sheaths somewhat compressed, smooth or rough, villous at the apex on the outside; 
blades lanceolate or linear-lanceolate, acuminate, those on the innovations and at the lower 
part of the stem strongly narrowed at the base, and at length disarticulating, those on 
the upper part of the stem usually rounded at the base, up to 3 dm. long and 4.5 cm. 
wide, usually shorter and narrower, smooth excepting on the margins, usually glabrous ; 
racemes commonly 6-20, rarely double that number, 5-12 cm. long, digitate, or some- 
times corymbose-paniculate in 2-4 alternate fascicles, the rachis densely barbed at the nodes 
and at the apex of the pedicels with long hairs, the internodes long-hairy, the pedicel grown 
to the callus of the sessile spikelet, and both adnate to the rachis; sessile spikelet with a 
long-hairy callus 2-3. mm. long, the first scale glabrous, 4.5-5 mm. long, the second scale 
about as long, sparsely long-hairy toward the apex, the fourth scale bearing a usually im- 
perfect awn 8-12 mm. long; pedicellate spikelet with a long-hairy callus about 1.5 
mm. long, the first scale about 4.5 mm. long, and, like the nearly equal second, sparsely 
long-hairy, the fourth scale bearing an awn similar to that of the sessile spikelet. 
TYPE LOCALITY : Guadeloupe. 
DISTRIBUTION : Mexico to tropical South America, and north in the West Indies to Guadeloupe ; 
Jamaica (according to Fawcett). 
ILLUSTRATION : Kunth, Rev. Gram. pi. 99. 
2. Ischaemum rugosum Salisb. Ic. Stirp. Rar. 1. 1791. 
Ischaemum segetum Trin. Mém. Acad. St. Petersb. VI. 2: 294. 1832. 
Stems erect or ascending, branched at the base, up to 1 m. tall, glabrous; leaf-sheaths 
compressed, keeled below, glabrous, or sometimes pubescent near the apex; blades up 
to 3 dm. long and 1.5 cm. wide, usually hirsute on both surfaces; racemes in pairs, 3-6 
em. long, the rachis internodes with the exterior angle ciliate with long hairs, the in- 
terior angles with very short hairs; sessile spikelet, including the callus, about 5 mm. 
long, the first scale cartilaginous below and marked with 5-6 transverse irregular eleva- 
tions, the upper portion membranous and veined, the second scale usually a little exceed- 
ing the first, coriaceous on the back, keeled, the third scale hyaline, the fourth scale also 
hyaline and bearing a perfect awn 15-20 mm. long, the column brown and about equaling 
the subulate portion ; pedicellate spikelet shorter than the sessile one, the first scale with 
2-4 usually less distinct transverse elevations, or these sometimes almost wanting, the 
fourth scale bearing an imperfect awn about 5 mm. long, the pedicel ciliate. 
TYPE LOCALITY: Orissa, India. , wae ; ; ; 
DISTRIBUTION: Introduced at Madruga, Cuba. Widely distributed in tropical Asia and 
Malaysia. ; . 
ILLUSTRATION : Salisb. Ic. Stirp. Rar. pl. 1. 
