70 AIRA ALPINA. 
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. 
Flowers at the commencement of August, and becomes ripe 
in the middle of September. 
Dr. Parnell figures a viviparous variety called Vévipara. 
