588 THE GEASS FAMILT. 



Mediterranean to the Arctic regions, and in North America. Abundant in 

 Britain. Fl. summer. The alpine A. {A. alpina, Brit. FL, A. Icevigata, 

 Eng. Bot. t. 2102) is a mere variety, which in its least altered form only 

 differs in its lower statm-e, with shorter leaves, with the glumes more or 

 less enlarged, the awn adhering to it so much the higher as the glume is 

 more altered. In the commoner state the whole panicle is viviparous, all 

 the glumes being more or less elongated and foliaceous, without awns, 

 and contaLaing only very imperfect flowers or none at all. These varie- 

 ties are frequent at considerable elevations, or at liigh latitudes, and not 

 uncommon in the higher mountains of Scotland. 



2. VTavy Aira. Aira flexuosa, Luin. 



(Eng. Bot. t. 1519.) 



A much smaller and more slender plant than the ordinary form of the 

 tufted A., from 1 to \\ feet high, with very narrow leaves, roUed inwards 

 on the edges, and almost subulate. Panicle spreading, but not above 2 or 

 3 inches long ; the spikelets much fewer than ia the tufted A., but longer, 

 being usually 2 to 3 lines long, very sliining, with the fine, hair-like awns 

 protruding beyond the glumes. 



On heaths and hiUy pastures, throughout Europe and Russian Asia, 

 excepting some of the southern districts, in North America, and in Ant- 

 arctic South America. Generally distributed over Britain. JFl. summer. 



3. Grey Aira. Aira canescens, Linn. 

 (Eng. Bot. t. 1190. Corynephorus, Bab. Man.) 



A small, tufted perennial, of a glaucous or sUghtly purplish tinge, seldom 

 above 6 inches high, with fine convolute leaves. Panicle dense and narrow, 

 1 to 2 inches long. Spikelets about 2 hnes long, the outer glumes pointed, 

 quite concealing tlie small flowering ones. These are remarkable for their 

 awns, which are jointed in the middle, with a tuft of minute hairs at the 

 joint, and slightly thickened towards the top, the whole awn not projecting 

 beyond the outer glumes. 



In sandy situations, in central and southern Europe, extending eastward 

 to the Caucasus, and northward to southern Scandinavia. In Britain, only 

 known for certain on the sandy seacoasts of Norfolk and Suffolk, and in 

 the Channel Islands. Fl. summer. 



4. Early Aira. Airy prsecox, Linn. 

 (Eng. Bot. t. 1296.) 



A slender, densely tufted annual, 3 to 6 inches high, with short, very 

 fine leaves. Panicle contracted, i to 1 mch long. Spikelets rather more 

 than a line long, the outer glumes very scarious. Flowering glumes small, 

 cleft at the top, and slightly hardening, as in Oat ; the short, hair-like awns 

 shortly protruding beyond the outer glumes. 



In sandy and hiUy pastures, in central and southern Europe, and western 

 Asia, extending into Scandinavia, but not far to the north. Grenerally 

 spread over Britain, to the northern extremity of Scotland. Fl. spring. 



5. Silvery Aira. Aira caryophyllea, Linn. 



(Eng. Bot. t. 812. Hair-grass.) 

 A slender, graceful, tufted annual, seldom above 6 inches high, with 

 short, fine leaves, as in the eai-li/ A., but the panicle is loose and spreading, 



