This slender, graceful grass is found throughout the North Temperate Zone in Europe, N. Africa, and has been introduced into N. America. It is unknown in early plant beds. It is absent in Great Britain only in S.E. Yorks, and ranges as far as the Shetlands, up to 1400 ft., in the Highlands. It is native in Ireland and the Channel Islands.

The Silvery Hair Grass is a rupestral species, growing on rocky pastures or barren moorlands, being a xerophyte, and partly ericetal. With it one will find Harebells, Eyebright, and other lovers of dry soil.

It has a very loosely-rooted fibrous root. The stem is erect, terete, striate, with 2-3 joints, tufted, decumbent at the base, rough above. The leaves are bristle-like, short, blunt, rough, rigid, the edges involute and narrow. The ligule is long, rough, and striate, with a white membrane.

The flowers are in a panicle, which is widely branched, with single flower-stalks, and divided into three parts. The spikelets are small, egg-shaped, shining, rounded, purple below, the lower empty, egg-shaped, and longer than the flowering glume. The awn is longer than the glume, jointed, dorsal, twisted, originating from the middle of the palea, which is divided into two nearly to the base.

Silvery Hair Grass (Aira caryophyllea, L.)

Photo. A. R. Horwood - Silvery Hair Grass (Aira caryophyllea, L.)

This grass is 6-8 in. high. The flower is in bloom in May, June, and July. It is annual, propagated by seed.

The flowers are anemophilous. There are 3 stamens, and the stigmas are feathery, as in other wind-fertilized flowers. The anther-stalks are capillary. The anthers are oblong and forked at each end. There are 2 styles. The fruit is light and attached to the glume and palea, and is blown away readily by the wind.

Silvery Hair Grass is a sand-loving plant and requires a sand soil.

The Butterfly, The Grayling (Satyrus semele), and two moths, The Slender Clouded Brindle (Xylophasia scolopasina), Elachista elcochar-ella, are found on it.

Aira, Theophrastus, from Greek airo, I destroy, was the name of a grass - probably Darnel - which was poisonous. The second Latin name is given in allusion to the scent of cloves, which makes it attractive to Lepidoptera. It is called Mouse-grass.

Essential Specific Characters: 333. Aira caryophyllea, L. - Stem erect, leaves setaceous, short, narrow, sheaths rough below, panicle spreading, awn silvery, twisted.