﻿GRASSES OF SCOTLAND. 58 



tie above the base, and extending scarcely above the summit of the palea. 

 Inner palea membranous, linear, and entire at the margins, rather 

 shorter than the outer palea. Second floret elevated on a hairy pe- 

 dicle, and rather smaller than the lower floret, but similar to it in 

 every other respect. 



vivipera, a viviparous variety occasionally found on the 



Clova mountains. 



Obs. — Aira ccBspitosa is at all times readily distinguished from 

 Aira alpina in the awn arising from a little above the base of the 

 outer palea ; — whereas in A. alpina, the awn arises from a little above 

 the centre of the outer palea. (See Plate XXIII. Fig. 2.) 



From Aira flexuosa, in the awn of the lower floret not protruding 

 beyond the glumes of the calyx; — whereas in A.Jiexuosa the awn of 

 the lower floret protrudes more than one-third its length beyond the 

 glumes. (See Plate XXIV. Fig. 2.) 



This grass has a most unsightly appearance in meadows, pastures, 

 and parks, as it grows into large tufts, and forming irregularities on 

 the surface, which are termed by farmers rough-caps or hossacks, and 

 are with difficulty got rid of, especially when numerous. From the 

 extreme roughness and coarseness of the leaves, cattle seldom touch 

 it, and possessing but little nutritive properties, does not merit the at- 

 tention of agriculturists. It is said to grow in every kind of soil and si- 

 tuation, from the marsh to the dry sandy heath, but prefers moist clayey 

 soils, where the water stagnates. It forms a good under cover for game 

 and shelter for wild fowl. This grass is abundant in England, Scotland, 

 and Ireland. It is found also in Lapland, Norway, Sweden, Ger- 

 many, France, and Italy, as well as in the most northern parts of 

 North America and the United States. Its limit of altitude is about 

 1500 feet above the sea. 



Flowers in the third week of July, and ripens its seed about the 

 middle of September. 



36. Aira alpina.* 

 Smooth Alpine Hair- Grass. 



Specific Characters. — Awn arising from a little above the centre 



* Aira alpina, Smith, Hooker, Lindley. 



