520 THE GRASS FAMILY. [Azra. 
being more or less elongated and foliaceous, without awns, and containing 
only very imperfect flowers or none at all. These varieties are frequent at 
considerable elevations, or at high latitudes, and not uncommon in the 
higher mountains of Scotland. 
2, A. flexuosa, Linn. (fig. 1190). Wavy Aira.—A much smaller and 
more slender plant than the ordinary form of A, cespitosa, from 1 to 14 
feet high, with very narrow leaves rolled inwards on the edges, and almost 
subulate. Panicle spreading, but not above 2 or 3 inches long; the spike- 
lets much fewer than in A. cespitosa, but larger, being usually 2 to 3 lines 
long, very shining, with the fine, hair-like awns protruding beyond the 
glumes, Deschampsia flexuosa, Beauv. 
On heaths and hilly pastures, throughout Hurope and temperate Asia 
North America, and in South Chili and Fuegia. Generally distributed over 
Britain. Fl. summer. 
3. &. canescens, Linn. (fig. 1191). Grey Aira.—A small, tufted 
perennial, of a glaucous or slightly purplish tinge, seldom above 6 inches 
high, with fine convolute leaves. Panicle dense and narrow, 1 to 2 inches 
long. Spikelets about 2 lines long, the outer glumes pointed, quite con- 
cealing the 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. Corynephorus canescens, Beauv. 
In sandy situations, in central and southern Europe, extending eastward 
to North Asia and 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. FV. summer. 
4, &. preecox, Linn. (fig. 1192). Harly Aira.—A fslender, densely 
tufted annual, 3 to 6 inches high, with short, very fine leaves. Panicle 
contracted, } to 1 inch 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 Avena; the short, hair-like awns shortly pro- 
truding beyond the outer glumes. 
In sandy and hilly pastures, in central and southern EKurope, and 
western Asia, extending into Scandinavia, but not far to the north. 
Generally spread over Britain, to the northern extremity of Scotland. 
Fl. spring. 
5, A. caryophyllea, Linn. (fig. 1193). Silvery Aira, Hair-grass.— 
A slender, graceful, tufted annual, seldom above 6 inches high, with 
short, fine leaves, as in A. precox, but the panicle is loose and spreading, 
with long, capillary branches, usually in threes, often occupying half the 
whole height of the plant. Spikelets and glumes asin A. precox. 
In sandy and hilly pastures, with the same area as A. precox, and fally 
as common in Britain. £7. summer, rather early. 
XVIII. AVENA. OAT. 
Spikelets several-flowered (usually with 3 to 5 flowers, rarely more, or 
2 only), in a loose panicle. Glumes scarious, at least at the top; the 
outer empty ones lanceolate and tapering to a point; the flowering one 
smaller, 2-cleft at the top, each lobe tapering into a point, witha long, 
