69 



AIRA ALPINA. 



Linnaeus. Hookeb and Abnott. Pabnell. Babington. Lindlet. 



WlLLDENOW. WaHXENBEEG. 



PLATE XXI. A. 



Aira Icevigata, J. E. Smith. 



The Smooth Alpine Hair-Grass. 



Aira — To destroy. Alpina — 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 Jlezuosa 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. Pani- 

 cle upright, silky, brown. Apex drooping. Branches arranged 

 on the smooth rachis in pairs at certain distances. Spikelets 

 numerous, with exceedingly delicate footstalks, usually two, 

 though occasionally three, awned florets, the lower one not 

 protruding beyond the calyx. Calyx of two nearly equal mem- 

 branous smooth glumes. Upper glume three-ribbed, others 

 destitute of lateral ribs. Florets of two palea?, exterior one of 

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



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