438 GRAMINACE^. 



consisting of a single awned palea ; the upper flower perfect, of 

 2 palese, diaudrous, nearly equal, short, awnless. — Panicle con- 

 tracted or spike-like. 



A. odor alum, Linn. : panicle spiked, ovoid-oblong ; flowers pubescent, 

 shorter than the awns. 



Meadows and woods. Can. to Car. June — Aug. %. — Culm about a foot 

 high, erect, rather slender. Leaves short, more or less pubescent. Panicle 

 contracted into an oblong or ovoid-oblong spike, yellow when mature. When 

 cut and partially dry it gives out a very fragrant odor. Introduced from Europe, 

 but completely naturalized. Sweet-scented Vernal-grass. 



33. AIRA. Li7in. — Hair Grass. 



(From the Greek aipo), to destroy ; a name originally applied to a poisonous 

 plant, Lolium temulentum.) • 



Spikelets 2 — 3 -flowered ; the flowers without an abortive 

 rudiment TOtween them. Glumes 2, unequal, about as long as 

 the flowers. Palece thin and membranaceous, the lower one 

 awned on the back below the middle. — Flowers usually in a 

 compound spreading panicle. 



1. A.Jlexuosa Linn. : leaves setaceous, smooth ; panicle loose, spreading, 

 trichotomously branched ; branches smoothish, flexuous ; flowers scarcely 

 longer than the glumes ; awn geniculate, longer than the paleae. 



Dry rocky banks. Can. to Car. W. to Mich. June. ll-.—Cidm 1—2 kei 

 high, smooth. Leaves mostly radical or near the base of the culm, involute, 

 slender. Panicle capillary, loose, whitish, the lower branches somewhat 

 whorled. Common Hair-grass. 



2. A. caspitosa Linn. : leaves flat, scabrous ; panicle at length diffuse ; 

 glumes about as long as the paleaj ; awn short, straight. A. aristulata 

 Torr. Fl. 



Wet places. Can. to Penn. June, July. %.— Culms 2 — 3 feet high, cespi- 

 tose, smooth. Leaves narrow, rough above, smooth beneath. Panicle large, 

 oblong or pyramidal, capillary, dull purplish ; the branches somewhat whorled. 



Tufted Hair-grass. 



3. A. atropurpurea Wahl. : leaves flat ; panicle divaricate, of few spike- 

 lets ; flowers much shorter than the glumes ; paleae a little hairy at the 

 summit ; awn from the middle of the back, nearly twice as long as the 

 flowers. (^Tm-r. N. Y. Fl.) 



High mountains of Essex County, N. Y. Aug. 71. l—CwZm 8— 15 inches 

 high, erect, slender. Leaves short, smooth. Panicle loose, purplish or yellow- 

 ish-green ; branches mostly in pairs and flexuous. 



Purple Alpine Hair-grass. 



4. A. prcecoz Linn. : leaves setaceous ; panicle somewhat spiked ; flow- 

 ers scarcely villous at the base, about as long as the glumes ; awn twisted, 

 inserted below the middle, longer than the flowers. Avena jyrcecox Beauv. 



Sandy fields. N. J. to Virg. ■ June. (T).— Culms 3 — 4 inches high, cespitose, 

 smooth, leafy. Leaves short, smocth. Panicle somewhat compact, few-flow- 

 ered, greenish. Introduced ? Early Hair-grass. 



