GRAMINE^E. (GRASS FAMILY.) 633 



icle broad, more slender ; spikelets smaller (f " long), broadly ovate and very 

 obtuse; lower glume very obtuse. (P. sphaerocarpon, Ell.) N. Y. to Ga,, 

 and westward. 



18. P. microcarpon, Muhl. Like the last; the broadly lanceolate 

 leaves nearly similar, but usually longer (8' long or less), distinctly nerved; 

 panicle soon exserted on a slender peduncle, rather narrower, with numerous 

 slender branches and very many-flowered (3 - T long) ; spikelets about " 

 long, ovoid, smooth or smoothish ; lower glume orbicular and very small. 

 Dry or moist thickets, Penn. to Mich., Neb., and southward. July - Sept. 



^. .M. Culm-leaves linear or sometimes narrowly lanceolate (basal often lanceolate) 

 primary nerves often indistinct or none; spikelets small. 



19. P. depauperatum, Muhl. Culms simple or branched from the 

 base, forming close tufts (6-12' high), terminated by a simple and few-flow- 

 ered contracted panicle, often much overtopped by the narrowly linear and 

 elongated (4 - T) upper leaves ; spikelets f- 1^ long, oval-obovate, commonly 

 pointed when young ; lower glume ovate. Varies, with the leaves involute, 

 at least when dry (P. involutum, Torr.), and with the sheaths either beset 

 with long hairs or nearly smooth ; the panicle either partly included, or on a 

 long and slender peduncle. Dry woods and hills ; rather common. June. 



20. P. COnsanguineum, Kunth. Culms slender, 1-2 high, often de- 

 cumbent and rooting below ; nearly glabrous or the sheaths and leaves some- 

 what pubescent or villous; panicle small, with rather few spreading few- 

 flowered branches ; spikelets 1 - 1" long, oblong-obovate, acutish. Dry woods, 

 Norfolk, Va., and south to Fl. and Tex. 



21. P. dichotomum, L. ! Culms (8' -2 high) at first mostly simple, 

 bearing a more or less exserted spreading compound panicle (1 -3' long), and 

 linear to linear-lanceolate flat leaves (those tufted at the root usually ovate- 

 lanceolate and very short, thickish) ; but commonly branching later in the 

 season, the branches often clustered, and bearing nearly simple and included 

 small panicles ; spikelets - - f " long, elliptical, obtuse, downy or smooth ; 

 lower glume roundish. Common everywhere. Very variable both in habit 

 and in the amount of villosity (depending upon the soil, exposure, season, etc.), 

 so that it is difficult to specify any well defined varieties. The more conspic- 

 uous forms are (a) commune, with simple culms erect or ascending, and leaves 

 suberect, usually pale green (b)fasciculatum, with clustered leafy branches 

 and short peduncles, a common autumnal state and (c) grdcile, the culms 

 lax, very slender and elongated, with rather distant spreading leaves (usually 

 bright green), and mostly long-pedunculate panicles. 



22. P. laxiflorum, Lam. ! Closely resembling the last species, in its 

 several forms ; distinguished by the larger acutish spikelets (nearly or quite 

 1" long). Common. 



3. ECHIN6CHLOA. Spikelets imbricated-spiked on the branches of m* 

 simple or compound raceme or panicle, usually rough with appressed stiff 

 hairs; lower palet of the sterile flower awl-pointed or awned. 



P. CRTJS-GALLI, L. (BARNYARD-GRASS.) Root annual; culms stout, 

 branching from the base (1-4 high); leaves lanceolate (^ wide or more), 

 rough-margined, otherwise with the sheaths smooth; spikes alternate (1-3' 

 long), crowded in a dense panicle ; glumes ovate, abruptly pointed ; glume 



