GRAMINE.*:. (grass FAMILY.) C17 



10. S. airoides, Torr. Culm tufted, often stout, erect, ^-3'^ hipli ; 

 leaves .strongly revolute and attenuate, rather rigid ; panicle oj>en and diffuse, 

 I)roadly pyramidal, glabrous; spikelets solitary on slender pedicels, 1" long; 

 lower glumes unequal, rather obtuse. — Neb. to Tex., and westward, 



S. Asi'i:KiF6Lirs, Thurb., a .similar but smaller species, with thinner and 

 shorter leaves very rough on the margin, tlie intiorescence scabrous, and spike- 

 lets smaller, with the glumes nearly etjual, is very common westward, and prob- 

 ably occurs within our limits — as also S. coxFtrsrs, Vasey (S. ramulosus of 

 authors, not Kuiith), a low slender annual, with very sliort culms and a deli- 

 cate diffuse panicle, the very small spikelets (^" long) on filiform-davate 

 ])edicels. 



* * * Kmptij rjlumrs almost equal; j>anide racemose-elonr/ated, oppn, the prcli- 

 eels capillary ; sheatlis naked at the throat ; sj>ikelets not uvj'requentl ij two- 

 Jiuirered : perennial. 



11. S. COmpressuS, Kunth. Very smooth, leafu to the top ; culms tufted, 

 stout, vcri/ jlat : sheaths Hatteued, much longer than the internodes; leaves 

 erect, narrow, conduplicate-channelled ; empty glumes acutish, about one third 

 shorter than the obtuse Howering one. — Bog.s, on Long Island and in the 

 pine-barrens of N. J. Sept. — Forming strong tussocks, 1-2° high. Panicle 

 8-12 long ; si)ikclets V long, purplish. 



12. S. serotinus, Gray. Smooth; culms very slender, fattish (8-15' 

 h\^h), few-leaved ; leaves very slender, channelled ; panicle soon much exserted, 

 the diffuse capillary branches scattered ; glumes ovate, obtuse, about half the 

 length of the flower. — Sandy wet places, Maine to N. J. and Mich. Sept. — 

 A very delicate grass ; the spikelets half a line long. 



29. AGROSTIS, L. Bekt-Grass. (PI. 7.) 

 Spikelets 1-fiowered, in an open panicle. Empty glumes somewhat e(|ual, 

 or the lower rather longer, usually longer than the flowering one, pointless. 

 Flowering glume and palet very thin, pointless, naked; the first 3-5-nerved, 

 frequently awned on the back ; the palet often minute or none. Stamens 

 chiefly 3. Grain (caryopsis) free. — Culms usually tufted, slender ; root com- 

 monly perennial. (Name from aypos, ajield, the place of growth.) 



§ 1. AGTvOSTIS proper. Palet manifest, but shorter than the glume. 



A. Alba, L. (Fiorix or "White Bext-Grass.) Kootstocks creeping 

 or stoloniferous ; culms \-2° high, often decumbent at base; leaves short, 

 flat, the ligule long and acute ; jjanicle contracted after flowering, greenish, 

 pur])lish or brownish, the I)ranches sliglitly rougli ; flowering glume nearlv 

 equalling tlie em])ty ones, 3-nerved, rarely short-awned. th(^ ])alft aliout half as 

 long. — Meadows and fields, a valuable grass; naturalized from ICu. and cul- 

 tivated, and ])erhaps native north and westward. 



Var. vl'lgAius, Thurb. (Ri;i> Tor. IIehi>'s-Grass of Penn., etc.) (PI. 7, 

 fig. 1, 2.) Panicle more or less sjireading after flowering; ligule shoi-t and 

 truncate. (A. vulgaris. With.) — Low meadows and pastures; nat. from Eu. 

 and cultivated, also perhaps indigenous. 



1. A. arachnoides, Ell. Culms (1° high) and leaves very slender; 

 panicle open, weak and drooping; glumes nearly equal, rougliish on the keel 

 and margins, the flowering glume shorter, with 2 minute bristles at the trun- 

 cate apex and a long exceedingly delicate awn on the back above the middle ; 

 palet minute. — Mo. to Ky., Tenn., and S. Car. 



