12 
(b) Sheathing bracts at some distance below the spikes and exceeded by them. 
11. A. Elliottii Chapm. FI.8. States, p. 581. (4. clandestinum Hale. ?) Culms 
1 to 2 feet high, bearded at the upper joints; leaves and sheaths purplish, hairy ; 
sheaths, particularly the upper ones, inflated, often crowded and imbricated, 3 to 4 
inches long; spikes becoming long exserted, in pairs (rarely 3 to 4); the bract dis- 
tant below the spikes; rachis very slender, hairs long and silvery; awn 3 to 4 
times as long as the glumes.—Delaware to Florida and west to Texas. 
12. A. brachystachyus Chapm. FI. S. States, Suppl. p. 668. Culms 2 to 4 feet 
high, compressed, branching from the upper joints, narrowly paniculate ; leaves 
linear, long, not hairy, rough on the margins; spikes very numerous, by pairs, 6 to 8 
lines long, 6 to 9 flowered; spikes very small; awn 4 to 6 lines long.—Florida (Dr. 
Chapman). 
13. A. arctatus Chapm. (Chapm. FI. 8. States, p. 668.) (A. tetrastachyus var. dis- 
tachyus Chapm.) Culms single, 2 to 3 feet high, the appressed branches narrowly 
paniculate; leaves and sheaths shaggy, with long white, mostly deciduous hairs ; 
spikes in pairs, 1 to 14 inches long, rather stout, closely 15- to 29-flowered; glumes 
rough, twice as long as the joints of the rachis; hairs of the rachis few and short; 
stamen 1,—Florida (Dr. Chapman). 
14. A. argyrzeus Schultes. (4. argenteus Ell.: Gray’s Manual, 6th ed., p.637.) 
Culms, 2 to 3 feet high, smooth, branching; leaves long, linear, 6 to 10 inches long; 
culm and leaves smooth; branches 1 to 2 from each upper joint, long exserted ; spikes 
in pairs, 3 to 8 inches long; peduncle stout, with dense white silky hairs; joints of the 
rachis rigid, as long as the hispid, serrate spikelet; stamens, 3; awns, 3 to 4 times 
longer than the glumes.—Old fields and woods, Maryland to Florida and west to 
Texas. Var. TENUIS much more slender, leaves narrowly linear, spikes few.—Texas. 
15. A. Cabanisii Hack., in Flora, 1885, p. 133. Culms, 2 to3 feef high, slender, 
branching from the lower one-third to one-half; lower branches solitary or in pairs, 
primary ones elongated arcuate-spreading, of 1 to 2 glabrous nodes, secondary ones 
single or, none, short ; common peduncle densely barbed at the apex, spikes about 2 
incheslong, spikelets much as in A. argyr@us.—Pennsylvania to Florida (fide Hackel). 
§ 3. AMPHILOPHIS. 
Racemes digitate or panicled, all pediceled; joints of the rachis and 
pedicels with a translucent longitudinal median line; flowering glume 
pedicel like, tapering into an awn. 
16. A. provincialis Lam. Ency. I. p. 376. (A. furcatus Muhl.) Culms 3 to 6 feet 
high, rigid; the sammit and usually some lateral branches terminated by the 2 to 5 
approximate, rigid spikes 3 to 4 inches long, 20 to 26 jointed; joints of the rachis and 
pedicels sparsely ciliate; spikelets 3 to 4 lines long; lower glume lanceolate, rigid, 
bidentate, firmly scabrous; second glume membranaceous, keeled in the middle ; 
third and fourth scarious; the fourth awned; fifth 1 line long, fimbriate at apex; 
pediceled spikelet as long as the sessile one; first glume 13- to 15-nerved; the other 
glumes as in the sessile spikelet except the awn of the fourth glume; stamens 3.— 
Common east of the Rocky Mountains. 
17. A. Hallii Hack. (Gray’s Manual, 6th ed., p. 638.) (A. glaucus Torr.) Culms 
3 to 6 feet high, stout, smooth, glaucous; lateral branches exserted and sometimes 
nearly as long as the main culm; spikes 2 to 5, usually 3, digitate, 2 to 4 inches long, 
10 to 15 joints; the rachis and pedicels more or less villose, with white or straw-col- 
ored hairs; spikelets 4 to 5 lines long, the pediceled ones usually a little longer than 
the sessile ones; first glume linear-lanceolate, smooth or glaucous, except near ‘the 
apex, 9- to 11-nerved, one-fifth longer than the second glume.—Great Plains, from 
Montana to Mexico. 
A, Hallii is generally distinguished from 4. provincialis by its thicker and more 
succulent stem and leaves, its glaucous appearance, its usually larger spikes, and 
flowers which are conspicrfously silky-hairy. 
