64 POACEAE 
beneath, rough above and somewhat hirsute near the base : racemes in pairs, exserted, or a 
little included in the narrow spathes, 2-3 em. long: sessile spikelet 3-4 mm. long, exceed- 
ing the internode, the awn 1-1.5 em. long, more or less contorted, slightly twisted at the 
base ; pedicellate spikelet wanting, or a minute rudimentary scale, the pedicel considerably 
exceeding the sessile spikelet. 
In sandy soil, Florida to Mississippi. Fall. 
17. Andropogon arctàtus Chapm. Stems 1-1.5 m. tall, branched toward the sum- 
mit, the branches in 1's-3's: leaf-sheaths, at least the lower ones, more or less densely 
appressed-hirsute at the summit ; blades erect, 3 dm. long or less, 5 mm. wide or less, the 
upper surface rough, the lower usually densely appressed-hirsute toward the base : racemes 
in pairs, rarely in 3’s or 4’s, rather stout, dark gray, 2.5-4 cm. long, long-exserted : sessile 
spikelet 5-6 mm. long, about twice as long as the internode, the awn more or less con- 
torted, 1-1.5 em. long ; pedicellate spikelet usually present, consisting of a single scale, the 
pedicel considerably shorter than the sessile spikelet. 
In low pine lands, Florida. Fall. 
18. Andropogon argyraéus Schult. Stems tufted, 8-12 dm. tall, about twice as long 
as the basal leaves, the branches in 1’s-3’s: leaf-sheaths smooth or rough, glabrous or 
hirsute ; blades 3 dm. long or less, 3 mm. wide or less, rough : racemes in pairs, rather 
stout, silvery gray, 3-5 cm. long, long-exserted, the hairs on the summit of the internodes 
13-2 times their length : sessile spikelet 5-6 mm. long, about twice as long as the inter- 
node, the first scale appressed-pubescent between the nerves, acuminate from about the 
lower third, nerveless between the keels and usually deeply depressed, the awn more or 
less contorted, 1.5-2.5 cm. long; pedicellate spikelet of a single scale, 1-3 mm. long, the 
pedicel usually a little shorter than the sessile spikelet. 
In dry soil, Delaware and Maryland to Florida, and Texas; also in Indian Territory and Mis- 
souri, and probably southward tothe Gulf. Fall SILVER BEARD. 
19. Andropogon Cabanisii Hack. Stems 6-10 dm. tall, the branches in 1’s or 2’s: 
leaf-sheaths smooth or a little roughened ; blades 2.5 dm. long or less, 2-4 mm. broad, 
smooth beneath, rough above: racemes in pairs, 4-7 cm. long, grayish, the hairs at the 
apex of the internodes as long as or a little exceeding them, rather scant: sessile spikelet 
6-7 mm. long, broadly lanceolate, tapering from the middle, about twice as long as the 
internode, the first scale strongly hispidulous and 2-3-nerved between the keels, the nerves 
running the entire length of the scale; pedicellate spikelet of a single hispidulous scale 
3-3.5 mm. long, the pedicel about $ as long as the sessile spikelet. 
In dry soil, Pennsylvania (according to Hackel) and Florida. Summer. 
20. Andropogon Scribneriànus Nash. Glaucous. Stems tufted, 3-10 dm. tall, 
twice as long as the basal leaves, rather sparsely branched above : leaf-sheaths shorter than 
the internodes, smooth and glabrous ; blades 1 dm. long or less, 2.5 mm. wide or less, the 
upper surface minutely pubescent and also often hirsute near the base: racemes in pairs, 
stout, long-exserted, 4—7 cm. long, bright silvery white, the hairs on the internodes copious, 
those at the summit about twice the length of the internodes: sessile spikelet 5-6 mm. 
long, about twice as long as the internode, the first scale narrowed from about the middle, 
glabrous and shining between the keels, the internerve flat or nearly so, the awn of the 
fourth scale more or less contorted and bent, somewhat twisted below, 1-1.5 cm. long ; 
pedicellate spikelet wanting, or present as a small scale 1.5 mm. long or less, the pedicel 
equalling or a little shorter than the sessile spikelet. 
In dry pine lands, Georgia and Florida. Spring and summer. 
21. Andropogon furcàtus Muhl. Stems 1-2 m. tall: leaf-sheaths glabrous or some- 
times slightly hirsute ; blades 6 dm. long or less, 12 mm. wide or less, smooth beneath and 
glabrous or rarely a little hirsute, more or less roughened above and hirsute at the base : 
racemes in 2's-6's, 5-10 cm. long, stout, long-exserted, the hairs of the internodes and 
pedicels grayish white, 1-2 mm. long: sessile spikelet 7-10 mm. long, the outer 2 scales 
more or less hispidulous, the awn 7-15 mm. long, geniculate, twisted at the base ; pedicel- 
late spikelet as large as or a little smaller than the sessile, staminate, awnless. 
ih In dry or moist soil, Maine and Ontario to Manitoba, Florida, Kansas and Texas. Summer and 
all. 
22. Andropogon chrysocómus Nash. Stems 7-15 dm. tall, the branches in 
l's-3's: leaf-sheaths smooth and glabrous ; blades 3 dm. long or less, 7 mm. wide or less, 
smooth beneath, a little roughened above: racemes in 2's-4's, 5-9 cm. long, stout, long- 
exserted, the hairs of the internodes and pedicels about 3 mm. long, usually yellow : ses- 
sile spikelet about 1 cm. long, with a basal ring of short hairs, the outer 2 scales hispid on 
the nerves, the awn of the fourth scale twisted at the base, geniculate, 10-12 mm. long ; 
pedicellate spikelet awnless. 
In dry soil, Kansasto Texas. Summer and fall. 
