AIRA ALPINA. 69 



AIRA ALPINA. 



LINNAEUS. HOOKER AND ARNOTT. PARNELL. BABINGTON. LINDLEY. 

 WILLDENOW. WAHLENBERG. 



PLATE XXI. A. 



Aria Icevigata, J. E. SMITH. 



The Smooth Alpine Hair-Grass. 

 Aira To destroy. Alpine Mountain. 



AN uncommon and useless Grass, not seen at a less elevation than 

 three thousand feet. 



Found on Ben Lomond, Ben Arthur, and moist rocks in Angusshire, 

 and said to be found in Wales. 



Native of Lapland, Scotland, and North America. 



Distinguished from Aira flexuosa by the awn rising from above the 

 centre of the palea, and not extending beyond the apex of the palea. 



Stem upright, circular, and polished, carrying three or four narrow, 

 acute, mostly involute, strongly-ribbed leaves, rough on inner surface 

 and margins, smooth on back, with smooth striated sheaths. Joints 

 smooth. Inflorescence compound panicled. Panicle upright, silky, 

 brown. Apex drooping. Branches arranged on the smooth rachis in 

 pairs at certain distances. Spikelets numerous, with exceedingly deli- 

 cate footstalks, usually two, though occasionally three, awned florets, 

 the lower one not protruding beyond the calyx. Calyx of two nearly 

 equal membranous smooth glumes. Upper glume three-ribbed, others 

 destitute of lateral ribs. Florets of two palese, exterior one of lowest 

 floret shorter than the glumes; oval in shape; base hirsute; apex 

 jagged. Keel somewhat rough, having a brief rough awn rising from 

 a little above the centre, and extending to the apex of the palea. 

 Inner one rather shorter and membranous. Root perennial and fibrous. 

 Length from twelve to eighteen inches. 



