^ GRAMINACE^. 429 



2. A. gracilis Ell. : culm very slender, erect ; panicle spiked, the flow- 

 ers appressed ; lateral awns rather shorter than the paleae, erect ; middle 

 one longer, bent, not twisted ; lower palea spinulose on the keel. ( Torr. 

 N. Y. FL) A. slricta Darlingt. not o? Mich. 



Sterile sandy soils. N. Y. to Car. Sept. 0. — Culm 4 — 15 inc"hes high, 

 smooth. Leaves very narrow, convolute when dry. Panicle 2 — 5 inches long, 

 slender. A striata Mich, is probably confined to the southern states. 



Slender Three-awned Grass. 



3. A. purpurascens Pair. : culm filiform, erect, simple ; leaves very nar- 

 row, flat ; flowers in a long spiked panicle ; awns nearly equal, twice as 

 long as the paleae, divaricate. " 



Sandy fields and woods. Mass. to Penn. ? Sept. %.. — Culm 2 — 3 feet high. 

 Leaves filiform at the extremity. Panicle elongated, loose, purple. Introduced ? 



Purple Three-awned Grass. 



V. Agrostejs. Spikelels \-Jioivered, rarely vjith the subulate rudi- 

 merit of an upper flower. Glumes and palece 2, memhranaceoously 

 herbaceous ; lower palea often awned. Stigma mostly sessile. 



17. MUHLENBERGIA. ^Sc/wr*.— Muhlenbergia. 



(In honor of the late Henry Muhlenlerg, D.D., one of the most distinguished 

 American botanists.) 



Glumes 2, very minute, unequal, one scarcely perceptible. 

 Paleee much longer than the glumes, linear-lanceolate, nerved, 

 hairy at base ; the lower one terminating in a long slender bris- 

 tle. — Panicle more or less contracted. 



1 . M. diffusa Sckreb. : culm decumbent, diffuse ; leaves linear-lanceolate ; 

 panicle slender, branched, the branches appressed ; bristles about twice as 

 long as the palea. 



Woods and pastures. N. Y. to Car. July. %. — Culm 12 — 18 inches long, 

 compressed, geniculate, branched. Leaves rough. Panicles terminal and lat- 

 eral, very slender ; bristle purplish. 



SpreadingMuhlenbergia. Drop-seed Grass. 



2. M. erecta Schreb. : culm erect, simple ; leaves lanceolate, pubescent ; 

 panicle simple, loose ; awn twice as long as the palea ; upper palea with 

 an awn at base lodged in a groove on the back. Brachyehjtrum aristatum 

 Beauv. 



Rocky hills. Can. to Car. July. ^i-. — Root creeping. Culm 2 — 3 feet high, 

 erect, slender. Leaves 4 — 6 inches long. Panicle simple, racemose, erect. 

 Lower palea with a very long awn. Erect Muhlei^bergia. 



18. CINNA. Linn.— Cmn?i. 



(From the Greek Kiwa^ a kind of grain.) 



Glumes nearly equal, compressed, the upper one 3 -nerved. 



Paleae 2, nearly equal, compressed, shortly stipitate, naked at 



the base ; the lower one larger, enclosing the upper, with a 



short awn near the summit. Stamen 1. — Panicle loose. 



