Parv 2, 1912] POACEAE 
Perennials. 
Leaf-blades flat, or sometimes complanate when dry, never terete 
nor involute, prominently keeled on the lower surface. 
First scale of the sessile spikelet densely pubescent. 
Sessile spikelet 4-5 mm. long. 
Sessile spikelet 7-9 mm. long. 
Internodes and pedicels glabrous on the back. 
ee and pedicels hirsute on the back with long erect 
airs. 
First scale of the sessile spikelet glabrous. 
Internodes of the rachis glabrous, or rarely with a few hairs on 
one side. 
Fourth scale of the sessile spikelet entire, awnless; 
usually glabrous. 
Fourth scale of the sessile spikelet deeply 2-cleft, bearing a 
perfect awn; pedicel ciliate with long hairs, 
Sessile spikelet 4mm. long, the fourth scale not cleft below 
the middle, the awn commonly less than 1 cm. long. 
Sessile spikelet 5 mm. long or more, the fourth scale cleft 
nearly to the base, the awn more than 1 cm. long. 
Pedicellate spikelet about 3 mm. long, of a single scale, 
empty, the pedicel ciliate on the outer margin, rarely 
glabrous. 
Pedicellate spikelet 5-8 mm. long, of several scales, 
usually enclosing a staminate flower, the pedicel with 
he outer margin long-hairy at the apex. 
Internodes of the rachis and the pedicels ciliate with long hairs. 
Fourth scale of the sessile spikelet 2-cleft nearly to the base, 
the third scale not colored. 
Sessile spikelet about 7 mm. long, the column of the awn 
included or barely exserted from the scales ; stems com- 
monly sparingly branched. 
Sessile spikelet 3.5-5 mm. long, the column of the awn 
pedicel 
usually much exserted; stems commonly much branched. 12. 
Fourth scale of the sessile spikelet entire or shortly 2-toothed, 
the third scale usually colored. 
Stems tufted ; no Jong rootstocks nor stolons. 
Hairs more than twice the length of the internodes. 
Hairs usually much shorter than the internodes. 
Hairs at the apex of the internodes short, 1-3 mm. 
long; plant usually green or purplish, rarely 
glaucous. 
Hairs grayish-white, rather sparse, the spikelets 
plainly visible through them. 
Sessile spikelet 5-7 mm. long, rarely longer. 
Sessile spikelet 10 mm. long. 
Hairs on the internodes and pedicels silvery-white, 
dense, nearly concealing the spikelets. 
Hairs at the apex of the internodes 45 mm. long; 
plant glaucous, the leaf-sheaths much compressed. 17. 
Stems not tufted, with long creeping rootstocks and long 
extra-vaginal innovations. 
Pedicellate spikelet of 4 scales, with a staminate flower ; 
leaf-blades spreading ; plant glaucous. 
cael spikelet of 1 or 2 scales, empty; leaf-blades 
Sessile ‘spikelet 6-7 mm. long; pedicellate spikelet oar 
a single scale which has a single short awn. 
Sessile spikelet 9-10 mm. long ; pedicellate aeliee 
20 
of 2 scales, the first scale 3- awned. 
Leaf-blades terete or involute, not keeled on the lower surface, the 
upper surface with a broad white median band of spongy tissue. 
Internodes of the rachis and the pedicels ciliate on the margins; first 
scale of the sessile spikelet few-nerved. 
Spike-like racemes long-hairy, the spikelets nearly concealed in 
the hairs; fourth scale of the sessile spikelet 2-cleft for one 
quarter to one half its length, the column of the awn much ex- 
serted, tightly spiral. 
Spike-like racemes sparsely hairy, the spikelets plainly evident ; 
fourth scale of the sessile spikelet entire or minutely 2- toothed) 
the loosely spiral column not exserted. 
Internodes of the rachis glabrous, the pedicels with but a few hairs 
near the apex; first scale of the sessile spikelet 11-13-nerved. 
° 
7. 
9. 
10. 
13. 
14. 
15 
21. 
PeSys 
101 
Myosurus, 
. Susemiglabrum, 
. SL 
domingense. 
S. Salzemanni. 
re 
S. 
lenerum, 
semiberbe., 
S. cirratum, 
an $ 
18. S, 
S. 
22. S. 
23. S. 
Schottit. 
condensaium. 
. Muelleri. 
scoparium, 
acuminatum, 
neo-mexicanum. 
littorale. 
maritimum, 
. Stoloniferum, 
. riaristalum., 
gracile. 
cubense. 
multinervosum, 
1. Schizachyrium brevifolium (Sw.) Nees; Mig. Fl. Ind. 
Bat. 3: 495. 
Andropogon brevifolius Sw. Prodr. 26. 1788. 
Andropogon obtustfolius Poir. in Lam. Encye. Suppl. 1: 583. 
1855. 
1810. 
