GRAMTNE.f:. (r.RASS FAMTI.V.) C41 



about half the length of the inner, wliich is 8- 10 ' lon^;; awns 2-4" long — 

 IMinn. and Dak. to Tex. — Very variable. 



■<-* ■*-*■ Middle f/lume shelter than the lower ; perennials, simple-stemmed, 2 - 4'^ high. 



8. A. purpurascens, I'oir. (PI. 8.) Glabrous; leaves long, rather 

 iuv(»lute; sijikt-kts in a (10-18') long spiked panicle; lower glumes 1-nerved; 

 aims much longer than the spikelet, the middle one about 1' long. — Mass. to 

 Micii., Minn., and southward ; common. 



9. A. lan^ta, Poir. Tall and stout; leaves tardily involute, rojK/Zj above, 

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

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



♦ * Awns united below into one, jointed icith the apex of the glume ; root annual. 



10. A. tubercul6sa, Nutt. Culm branched l)elow (6-18' high), tumid 

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

 about 2-riowered, the other elongated and several-tlowered ; lower glumes (T 

 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 (H-2' long) twisting together at tlie 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 o-tutttj, 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 Jlower short and blunt; lower glumes pointless. 



1. S. Richardsdnii, Link. Culm (1^-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-oldong fertile one, Avhich bears a tortuous awn 6-9" long. — Pleasant 

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

 Superior, Mont., and northward. 



« * Callus pnngentlji pointed, at maturiti/ villous-bearded ; Jloxcering glume sleri' 

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



2. S. aven^cea, L. (Black Oat-Grass.) (PI. 8.) Culm slender (1 - 

 2*^ high); leaves ahnost bristle-form; panicle ojien ; 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. sp^rtea, Trin. (Porcupine Grass.) Culm rather stout (U- 3" 

 high) ; panicle contracted ; fertile glume linear, f-l' long (including tiie long 

 callus), pubescent below, shorter than the lanceolate slender subulate-pointed 



41 



