GRAMINM. (GRASS FAMILY.) 641 



about half the length of the inner, which is 8-10" long ; awns 2-4" long. 

 Minn, and the Dakotas to Tex. Very variable. 



HH . ++ Middle glume shorter than the lower ; perennials, simple-stemmed, 2 - 4 high. 



8. A. purpurascens, Poir. (PI. 8.) Glabrous; leave? long, rather 

 involute ; spikelets in a (10- 18') long spiked panicle ; lower glumes i -nerved; 

 awns much longer than the spikelet, the middle one about V long. Mass, to 

 Mich., Minn., and southward ; common. 



9. A. lanata, Poir. Tall and stout ; leaves tardily involute, rough above, 

 rigid ; sheaths woolly ; panicle (1 - 2 long) spike-like or more compound and 

 open; glumes 1 -nerved, 6-8" long; middle awn V long. Del. to Fla. 



* # Awns united below into one, jointed with the apex of the glume; root annual 



10. A. tuberculosa, Nutt. Culm branched below (6 -18' high), tumid 

 at the joints ; panicles rigid, loose, the branches in pairs, one of them short and 

 about 2-flowered, the other elongated and several-flowered ; lower glumes (!' 

 long, including their slender-awned tips) longer than the upper, which is 

 tipped with the common stalk (about its own length) of the 3 equal diver- 

 gently-bent awns (1-J--2' long) twisting together at the base. Sandy soil, E. 

 Mass, to N. J. ; also Wise., Minn., and southward. 



20. STIPA, L. FEATHER-GRASS. (PI. 8.) 



Spikelets 1 -flowered, terete ; the flower falling away at maturity (with the 

 conspicuous obconical bearded and often sharp-pointed callus) from the mem- 

 branaceous persistent lower glumes. Fertile glumes coriaceous, cylindrical- 

 involute and closely embracing the smaller palet and the cylindrical grain, 

 having a long and twisted or tortuous simple awn jointed with its apex. 

 Stamens mostly 3. Stigmas plumose. Perennials, with narrow involute 

 leaves and a loose panicle. (Name from a-Tv-try, tow, in allusion to the flaxen 

 appearance of the feathery awns of the original species. In our species the 

 awn is naked.) 



* Callus or base of the flower short and blunt ; lower glumes pointless. 



1. S. Kichardsbnii, Link. Culm (l|--2 high) and leaves slender; 

 panicle loose (4 5' long), with slender few-flowered branches; lower glumes 

 nearly equal, oblong, acutish (2| - 4" long), about equalling the pubescent 

 linear-oblong fertile one, which bears a tortuous awn 6 - 9" long. Pleasant 

 Mountain, near Sebago Lake, Maine, Mt. Marcy, N. Y., north shore of Lo 

 Superior, Mont., and northward. 



* # Callus pungently pointed, at maturity villous-bearded ; 'flowering glume slew 



der and minutely bearded at the tip ; empty glumes taper-pointed. 



2. S. avenacea, L. (BLACK OAT-GRASS.) (PI. 8.) Culm slender (1 - 

 2 high) ; leaves almost bristle-form ; panicle open ; fertile glume blackish, 

 nearly as long as the lower ones (about 4" long) ; the awn bent above, twisted 

 below (2-3' long). Dry woods, S. New Eng. to Wise., and southward. 



3. S. spartea, Trin. (PORCUPINE GRASS.) Culm rather stout (1|- 3 

 high) ; panicle contracted ; fertile glume linear, f -1' long (including the long 

 callus), pubescent below, shorter than the lanceolate slender subulate-poir.teJ 



