142 AVEKA. [CLASS ni. OBDER 11. 



Hooker, British Flora, vol. i. p. 53. Lindley, Synopsis, Supplement, 

 p. 333. English Botany, Supplement, t. 2684. 



Root fibrous. Stem erect, stout, compressed, especially below, stri- 

 ated and rough, about three feet high. Sheaths long, close, remarka- 

 bly compressed and sharply keeled, strongly striated, and very rough. 

 Leaves broad, fiat, nearly of the same width throughout, with a broad, 

 acute, sharp point, rough, the margins serrated with sharp cartilagi- 

 nous teeth, striated, and at the back having a remarkably sharp, thin, 

 projecting keel, the upper leaves very short. Ligula pale, thin, and 

 membranous : those of the upper leaves lanceolate acute; of the lower 

 oblong, mostly torn. Inflorescence an erect, spreading panicle, about 

 four inches long; its branches'rough and angular, scarcely subdivided, 

 arising in alternate half-whorls. Spikelets erect, long, close, linear, 

 afterwards spreading, and Saltish. Glumes lanceolate-acute, unequal, 

 pale, thin, and membranous : the outer smallest, with a rough keel ; the 

 inner with two lateral rough ribs and keel. Florets from five to seven, 

 rather remote, each (except the lower one) upon a roughish footstalk, 

 and having towards the top a tuft of white shining hairs. Glumelles 

 unequal: the outer obscurely four-ribbed and keeled, roughish, varie- 

 gated with green purple and white ; the upper part pale, thin, and 

 membranous, often torn at the extremity, the keel above the middle of 

 the valve terminating in a long, slender, rough, twisted aim ; inner 

 valve thin, pale, and membranous, with two slender, downy, lateral 

 ribs. Stiymas loose, feathery. Anther long, narrow, yellow. 



Habitat. Glen Sannox, on the ascent of Goat-fell from Loch Ran- 

 noch, Isle of Arrau, Scotland Mr. Stuart Murray. 



Perennial ; flowering in July. 



For specimens of this rare and distinct species of grass, I am indebted 

 to the kindness of Mr. Murray, who had the good fortune to discover 

 it in one of his botanical excursions on the interesting Isle of Arran 

 during the summer of 1826, and who has since that time grown it in 

 the Glasgow Botanic Garden, where it has remained unaltered in all 

 its characters. 



6. A. pnbes'cens, Linn. (Fig. 184.) downy Oat-grast. Panicle erect, 

 nearly simple ; spikelets erect ; florets about three, rather longer 

 than the glumes; leaves .flat, downy, the margins smooth. 



English Botany, t. 1640. English Flora, vol. i. p. 164. Hooker, 

 British Flora, vol. i. p. 54. Sinclair, Hort. Gram. Woburn. p. 285. 

 Trise'tumpulet'cens, Pers. Lindley, Synopsis, p. 308. 



Root fibrous, and somewhat creeping. Stein erect, except at the 

 base, from one to three feet high, round, smooth, simple, leafy. Leaves 

 flat, spreading, short, linear, acute, hairy. Sheaths long, close, striated, 

 the upper ones nearly smooth, the lower hairy. Ligula of the lower 

 leaves short and acute ; of the upper oblong, and mostly torn. Inflo- 



