GRAMINE^E. (GRASS FAMILY.) 647 



10. S. airoides, Torr. Culm tufted, often stout, erect, $-3 high; 

 leaves strongly revolute and attenuate, rather rigid ; panicle open and diffuse, 

 broadly pyramidal, glabrous; spikelets solitary on slender pedicels, 1" long; 

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



S. ASPERIF6LIUS, Thurb., a similar but smaller species, with thinner and 

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

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

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

 authors, not Kunth), a low slender annual, with very short culms and a deli- 

 cate diffuse panicle, the very small spikelets ($" long) on filiform-clavate 

 pedicels. 



~* * # Empty glumes almost equal ; panicle racemose-elongated, open, the pedi- 

 cels capillary ; sheaths naked at the throat ; spikelets not unfrequently two- 

 flowered ; perennial. 



11. S. COmpr^SSUS, Kunth. Very smooth, leafy to the top ; culms tufted, 

 stout, very flat ; sheaths flattened, much longer than the internodes ; leaves 

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

 shorter than the obtuse flowering one. Bogs, on Long Island and in the 

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

 8- 12' long ; spikelets 1" long, purplish. 



12. S. serbtinus, Gray. Smooth; culms very slender, flattish (8-15' 

 high), few-leave d ; 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. BENT-GRASS. (PI. 7.) 



Spikelets 1 -flowered, in an open panicle. Empty glumes somewhat equal, 

 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, afield, the place of growth.) 



1. AGROSTIS proper. Palet manifest, but shorter than the glume. 



A. ALBA, L. (FIORIN or WHITE BENT-GRASS.) Rootstocks creeping 

 or stoloniferous ; culms 1-2 high, often decumbent at base; leaves short, 

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

 purplish or brownish, the branches slightly rough ; flowering glume nearly 

 equalling the empty ones, 3-nerved, rarely short-awned, the palet about half as 

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

 tivated, and perhaps native north and westward. 



Var. VULGARIS, Thurb. (RED TOP. HERD'S-GRASS of Penn., etc.) (PI. 7, 

 fig. 1,2.) Panicle more or less spreading after flowering ; ligule short 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, roughish 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. 



