504 
as the spikelet; second and third equaling the floret.—Throughout Texas. Often 
cultivated, 
18. P. reticulatum Torr. Culms 3to6dm., high, slender, weak, branching: leaves 
lanceolate, subcordate at base: panicle 5 to 10cm, long, rather dense; branches 
often subfasciculate, with some short appressed subdivisions: spikelets obovate, 
nearly 3 mm. long; first glume broad, one-fourth as long as the spikelet; second 
and third glumes conspicuously reticulate-veined, equaling the floret.—Along 
streams, western Texas and westward. 
NotTre.—Some forms of P. fusewn Swartz come here, but the generally spreading 
panicle places this species in the next section, 
66. Branches of the panicle numerous, rather closely flowered, spreading, mostly single, 
simple or with few short almost appressed subdivisions: spikelets sessile or short-pedi- 
celled, —POLYSTACHY 1. 
* Branches of the panicle wing-margined or flattened: perfect florets transversely rugose. 
19. P. fuscum Swartz. Culms 38 to &8 dm. high, branching, leafy: panicle 1 to 
1.5 dm. long; branches narrowly wing-margined, sparsely hairy, and with a tuft 
of fuscous pubescence in the axils: spikelets nearly 3 mm. long turgid; first glume 
deltoid, one-third as lopg as the second and third; these reticulate-veined, slightly 
exceeding the floret.—Open woods, central and western Texas. 
20. P. barbinode Trin. (Para Grass.) Culms 1 to 2 m. high, robust, villous at 
the nodes: leaves lanceolate, smooth; sheaths pubescent, especially at the base and 
throat: panicle 1.5 to 3 dm. long; axis angular; branches flexuous, somewhat vil- 
lous at the nodes: spikelets ovate, acute, 3 mm. long; first glume deltoid, one- 
fourth as long as the second and third; these slightly exceeding the floret.—Intro- 
duced and cultivated throughout the State in moist soil. 
** Branches of the panicle terete or angular: perfeet Norets smooth, 
+ Spikelets crowded in continuous or interrupted clusters along the branches. 
21. P. hians Ell Culms 2 to 6 dm. high, slender: leaves narrow: panicle about 
1dm. long, rather loose; branches slender, naked below, densely flowered near the 
ends: spikelets 2. mm. long, obovate; the empty glumes spreading, shorter than the 
prominent curved, clavate, imperfect floret: this exceeding the acute, perfect 
floret.—Low prairies throughout Texas, 
22. P. agrostoides Mull. (MuNnnro-Grass,) Culms 6 to 15 dm, high, somewhat 
compressed below, in tufts or bunches: leaves lance-linear, 3 to 6 din. long, smooth 
throughout: panicle 1.5 to 3 dm. long, usually with small lateral panicles in the 
upper sheaths; branches ascending: spikelets less than 2 mm. long, slightly or not 
at all curved at the acute apex; first empty glume about one-half as long as the 
second and third; these exceeding the floret.—Wet land, eastern Texas and east- 
ward, The small spikelets and form of the panicle give it very much the appearance 
of red-top (Agrostis vulgaris). 
23. P. anceps Michx. Culms & to 12 dm. high, compressed below, from scaly root- 
stocks: leaves lance-linear, 2 to 6 dm. long, usually smooth: panicle 1 to 3 dm. long 
usually with smaller lateral panicles subvaginate in the upper sheaths; branches 
ascending: spikelets 3mm. long, curved at the acute apex.—Woods and moist places 
throughout Texas, and eastward. Var. PUBESCENS Vasey has pubescent leaves and 
sheaths, slender panicle, and branches and spikelets smaller than in the species. 
+ + Spikeleis scattered or solitary: panicle almost diffuse except in some forms of No. 24. 
24. P. diffusum Swartz. Culms 2to4 dm. high, slender, erect, simple or branch- 
ing below: leaves narrowly linear, subinvolute and rather rigid, 1 to 3 dm, long, 
often pubescent: panicle 5 to 15 em. long, loose; branches 2 tod cm, long, capillary, 
spreading, bearing few short-pedicelled spikelets near the extremities and on the 
