AlRA. 



GRAMINE^E. 



451 



Culm 1-2 feet high, smooth. Leaves mostly in a radical tuft, 5-8 inches long, involute, 

 very slender. Panicle capillary, loose ; the lower branches somewhat verticillate. Glumes 

 whitfsh, tinged with purple, oblong-lanceolate. Flowers both perfect, with a tuft of hairs at 

 the base. Lower palea 2-nerved ; the awn arising from near the base, and about one-half 

 longer than the flower : upper palea notched at the summit. 



Dry rocky places, and in sandy pine woods : very common. Fl. June. A native also of 

 Europe. 



2. Aira atropurpurea, Wahl. Purple Alpine Hair-grass. 



Leaves flat ; panicle divaricate, of few spikelets ; flowers much shorter than the glumes ; 

 palea? a little hairy at the summit ; awn from the middle of the back, nearly twice as long as 

 the flowers. — Wahl. fl. Lapp. p. 37 ; Hook. fl. Bor.-Am. 2. p. 243 ; Kunth, enum. I. 

 p. 291. 



Culm 8-15 inches high, simple, erect, slender. Leaves 2-3 inches long, 1-2 lines 

 wide, smooth on both sides : sheaths smooth : ligule oblong, obtuse. Panicle loose ; the 

 branches mostly in pairs and flexuous. Spikelets broadly ovate. Glumes about 3 lines long, 

 often purplish, but sometimes yellowish-green, ovate-lanceolate, acuminate, a little roughened 

 on the sides, and minutely serrulate on the sharp keel. Flowers 2, perfect, with long hairs 

 at the base ; the upper one on a short, thick pedicel, scarcely half the length of the glumes, 

 their awns included. Lower palea ovate, obtuse, with summit a little hairy ; the awn thick, 

 and slightly twisted below. 



High mountains of Essex county. Fl. early in August. This interesting grass seems to 

 be identical with the Lapland plant of the same name. 



** Deschampsia, Beauv. Upper palea somewhat truncate and ^-toothed at the summit. Awn short, straight. 



3. Aira c^espitosa, Linn. Tufted Hair-grass, 



Leaves flat ; panicle finally diffuse ; flowers about as long as the glumes ; awn short, 

 straight. — Linn. sp. 1. p. 64 ; Pursh, fl. 1. p. 77 ; Muhl. gram. p. 85 ; Torr. fl. I. p. 

 132 ; Beck, hot. p. 402; Darlingt. fl. Cest. p. 65. A. ambigua, Michx. fl. 1. p. 61. A. 

 aristulata, Torr. I. c. Deschampsia casspitosa, Beauv. Agrost. p. 91. t. 18. f. 3; Kunth, 

 enum. 1. p. 286. 



Culm 2-3 feet high, erect. Leaves a line or more in breadth, rough above, smooth 

 underneath : sheaths smooth. Panicle oblong or pyramidal : lower branches about 5; upper 

 ones in threes. Glumes rather acute, of a leaden or dull purplish color. Flowers 2, hairy 

 at the base, both perfect ; the upper one on a hairy pedicel. Lower palea obtuse and lace- 

 rately toothed at the summit ; the slender awn at its base scarcely as long as the flower. 

 Sometimes there is a plumose abortive pedicel at the base of the upper flower. 



Shores of small lakes in the western parts of the State. Fl. June. This is a common 

 European species. 



57* 



