780 Oedeb 166.— GRAMINE^. » 



3 A. gracilis BU. Ciilm very slender, a foot or more high ; Ivs. setaraoua, scarce 

 1" wide, erect^ with short sheaths, pilous at the throat; panicle very slender; 

 spikelets somewhat remote, appressed; lateral awns short (6 to 7"), erect, interme- 

 dia/,e one longer (10 to 12"), spreading. — y Sandy places, Mass. to Ga., "W. to III 

 A grass of little value, as well as the other species of this genus. 



4 A. lan^ta Poir. Culm erect, 2 to 4f, hairy and branched below ; Its. linear, 

 fiat. If long, 2 to 3" wide, hairy, especially on the upper surface; sheaths longer 

 than the joints, chOied with a woolly iomenium ; branches of the erect, contracted 

 panicle, tomentous at base ; glumes unequal, longer than the pales ; awns about 

 equal, spreading, as long as the pale (4 to 6"), the middle rather longest. — 2| In 

 poor, sandy soils, S. States. Sept., Oct. (A. lanosa Ell.) 



5 A. spiciformis EU. Culm 1 to 3f high, simple ; Ivs. and sheaths glabrous, the . 

 latter shorter than the joints ; panicle dense-flowered, spike-like and cylindrical ; 

 glumes much shorter than tlie flower, both awned; middle awn of the flower long- 

 est, villous at the base, all three about as long as the pale. — y Wet pine barrens, 

 B. Car. to Fla. Sept., Oct. 



6 A. purpurdscens Poir. Culm erect, simple, fiUform, 2 — 3f; Ivs. very narrow, 

 flat, erect, a foot in length, with short, open sheaths; panicle long, loosely spicate; 



, spikelets on short, clavate, appressed pedicels; gls. 4 to 5" long, purplish; awns V 

 long, nearly equal, divaricate, twice the length of the glabrous pale. — y Sandy 

 woods. Northern States. Sept. (A. affinis Kunth. A. racemosa Muhl.) 



7 A. striota Mx. Upeight Aristida. Culm strictly erect, casspitous, branched, 

 1 — 3f; Ivs. straight, erect, pubescent, linear, convolute aboi'e; panicle long, 

 loosely racemous ; spikelets appressed ; gls. (3 to 5" long) unequal, ijery acute, lower 

 pales hairy at base ; awns twice as long as the pales, spreading, the middle one 

 the longest. — y Penn. to Pla. (Oh:ipman), "W. to Mich. 



8 A. oligantlia Mx. ( Ims erect, sparingly branclied, 12 to 20' high; pan. ra- 

 ceme-hke, remotely few-tiuwered ; gls. slwrt awned, equaling the palo (J'), which 

 bears 3 divaricate awns thrice its own length, the middle one some longer; Ivs. 

 involute setaceous. — y Prairies, 111. to Ark. and Va. 



9 A. tuberculosa Nutt. Culm erect (deolinate at base), 8 — 20', rigid, with 

 email tubercles in the axils of the numerous branches ; nodes tumid ; Ivs. long and 

 narrow-Unear ; pan. large, loose, simple ; spikelets pedicellate ; gls. nearly 1' long, 

 linear, awned; upper paleae involute, the awns 2' long, hispid upwards, twisted 

 together to near the middle, thence finally horizontally divaricate. — y A very sin- 

 gular species, in dry prairies, 111., Wis. to Ky., Tenn., also found in if. J. 



13. STIPA, L. Weather Grass. (Lat. stipa, a foot-stalk ; allud- 

 ing to the stipitate fruit.) Spikelets 1-flowered, the flower deciduous, 

 ■with its thick, bearded, pointed stipe ; glumes niembi'anous ; pales cori- 

 aceous, shorter than the glumes, the lower with a long, twisted or bent 

 awn, jointed at the apex; caryopsis striate; stamens 3 ; stigma plum- 

 ous.— 2^ Fls. paniculate. Lvs. very narrow. The long awns are deli- 

 cately hygroraetric twisting or untwisting according to the state of the 

 atmosphere. 



1 S. avenacea L. Black Oat Grass. Culm naked above, 2 — 3f ; lvs. smooth, 

 striate, setaceous, chiefly radical ; panicle spreading, somewhat 1-sided, 4 — 6' long, 

 at length diffuse, branches capillary, sohtary and in pairs ; glumes nearly equal, 

 mucronate, as long as the dark brown, cylindric fruit; scales 2, lanceolate; awn 

 twisted below, bent above, 2 — 3' in length. — U. S. and Can. (S. Virginica Pers.) 



2 S. jiincea Pursh. Culm 2 — 3f; lvs. convolute filiform, smooth inside, long; 

 pan. loose ; gls. loose, flliformly acuminated to more than twice tlifi length of the fruit ; 

 fr. attenuated at base into a stipe, which is a third of its length, stipe acute, pu- 

 bescent ; paleae obtuse, distinctly articulated to the awn, which is smooth and slen- 

 der, at length contorted and 4 — 6' in length. — y Prairies, 111., Mo. When in fruit 

 the pungent stipe adheres to everything that comes in its way. Aug. 



14. ORYZOP'SIS, Mx. Mountain Eice. (Gr. dpv^a, rice, oipig, ap- 

 pearance.) Spikelets 1-flowered ; glumes membranous-bordered, veined, 



