496 
bract; rachis joints and sterile pedicel clothed with long white hairs: sessile spike- 
let 4mm. long; tirst glume bidentate, nerveless and smooth except the two hispid 
keels; awn yellow, very slender, 1 to 3 cm. long. (Cinna glomerata Walt. A, 
macrourus Michx.)—Cominon in rich bottom lands, Eastern Texas to New Jersey. 
Var. PUMILUS Vasey is a remarkable dwarf form about 2 din. high, tufted and 
branching from the base,.—Seminole Cave, Val Verde County. 
6. A. Virginicus L. Culms 5 to 10 dm. high, compressed below, branched above; 
branches short, twice or thrice subdivided: panicle erect, rather slender and open, 
2 to 4 dm. long, of interrupted, loose cymose clusters; racemes in pairs, 2 to 3 em, 
long, of 8 to 10 joints, exceeded by the lanceolate bract; rachis joints and pedicels 
with long silky hairs, especially above: sessile spikelet 3 mm. long; first glume 
slightly bidentate, searious, smooth and nerveless except the 2 hispid keels; awn 
1.5 to 2.cm. long.—Common in rather poor dry soil, Eastern Texas to Illinois and New 
York, 
«+ Sheathing bracts at some distance below the racemes and exceeded by them. 
7. A. Blliottii Chapm. Culms 5 to 10 dm. high, bearded at the upper nodes, 
loosely branched above: leaves and sheaths usually pubescent: racemes in pairs 
(rarely threes or fours), becoming long exserted, 2.5 to 3 em. long, of 6 to 8 joints; 
rachis joints and pedicels long hairy: sessile spikelet 4 mm, long; first glume 
slightly bifid at the apex, smooth, and nerveless except the two hispid keels or with 
few hairs near the apex; awn 1 to 2 cm. long.—Eastern Texas to Florida and Mary- 
land, 
** Racemes not hairy ercept in No. 8, rather closely flowered with appressed spikelets; 
rachis joints and pedicels clavate thickened: floral glume cleft + from the apex. 
8. A. argyreeus Schultes. Culms 5 to 10 dm. high, slender, smooth, or rarely 
bearded at the upper nodes, loosely branched, the branches single or in pairs at the 
upper nodes, 1 to 2 dm. long: leaves smooth throughout: racemes in pairs (rarely 
threes), not fasciculate, 3 to 4 em. long, of 6 to 9 joints; rachis joints and pedicels 
densely long villous: sessile spikelet 5 to6 mm. long; first glume bidentate, slightly 
suleate, rather rigid, nerveless except the two hispid or bearded keels; awn about 
2 em. long.—Common in sandy soil, Central Texas to Delaware. Var. TENUIS Vasey 
is much more slender, with narrowly linear leaves and fewer branches.—Kastern 
Texas, 
v. A. provincialis Lam. Culms 1 to 2m. high, smooth, terete, branching above: 
racemes in pairs or often two or three pairs approximate and appearing digitate at 
the summits of the culm and few stout lateral branches, 6 to 8 em. long, of 18 to 25 
joints; pedicels and rachis joints sparingly ciliate on the margins: sessile spikelet 
7mm, long; first glume rigid, coriaceous, indistinctly 4 or o-nerved, scabrous; awn 
about Lem, long; palet 2 mim. long, fimbriate at the apex: pedicellate spikelet as 
long as the sessile one, staminate or perfect.—Texas to Montana and eastward to 
the Atlantic Ocean. 
10, A. Hallii Hack. Culms 1 to 2m. high, glaucous, terete, branching above: 
racemes usually in twes or threes or sometimes two or three pairs approximate at 
the summits of the culms and long lateral branches, 6 to 9 em, long, of 10 to 15 joints; 
pedicels and rachis joints villose: sessile spikelet 8 to 10 mm. lone: first glume 
5S 
prominently suleate, rigid; awn 3 to 10 mm. long; palet 4 mm. long, fimbriate at 
the apex: pedicellate spikelet longer than the sessile one, staminate.—On sandwhill- 
sides and borders of the mesas, Texas to Montana. Var, FLAVEOLUS Hack. has hairs 
of the rachis and pedicels straw color, denser and longer than in the species, and the 
first and second glumes of both spikelets often hairy near the apex, Var. MUTICUS 
Hack., of the high plains, has rachis caneseent with white hairs, spikelets 11 to 
12 mm. long, short-awned or awnless, 
