(See also p. 90)

Field Mouse Ear (Cerastium arvense, Linn.). No seeds of this plant have been found in preglacial beds. Its distribution is Europe, Arctic, X. Africa, Siberia, W. Asia to the Himalayas, N. America, Fucgia, Chili. This species is found in 69 vice-counties in Great Britain, and in Ireland, occurring generally, except in those cited by number (see vol.

I. pp. 67-69, for reference to counties by number), as follows: - 1, 2, 4, 5, 9 to 11, 35, 37, 41 to 48, 59, 69, 75, 76, 78 to 79, 84, 88-9, 97 to 112. It is more general south of Inverness, rarer in Scotland and in Ireland.

In its habitat it is much more confined to hilly regions, being found in sandy fields, waste places, in arable fields, sometimes on quite stony ground.

Having a more erect or rigid habit than its near ally Cerastium vulgatum (Sect. IX), it has short stems with branches 6-10 in. long, tufted ascending, with lateral shoots, and glandular, hairy all round. The leaves are linear, lanceolate, crowded on the basal shoots.

Its flowers are white, larger than in C. vulgatum, in many flowered cymes, the 5 petals, bifid, twice as long as the 5 sepals, which are oblong, lanceolate, erect, the sepals and bracts being more or less acute, the tip and margins membranous. The capsules are inclined, a little longer than the sepals, on an erect fruit stalk. The surface of the seeds is covered with acute tubercles.

A perennial species, Field Mouse Ear flowers between April and August.

Pollination is much as in the Greater Stitchwort (see Sect. VI). The flowers being white are conspicuous. The anthers mature as a rule before the stigmas. The honey is half-concealed in nectaries and secreted much as in Stellaria aquatica (Sect. VIII). There is every encouragement given in the nature of the floral mechanism and its adaptation to insects for cross-pollination by the agency of insects, but in their absence self-pollination is not precluded. In addition to bisexual flowers there are occasionally smaller ones which have only stigmas, and only degenerate stamens if they have any. It generally has the hermaphrodite and female flowers on different plants, but occasionally the hermaphrodite and female flowers occur on the same plant. Occasionally there are hermaphrodite flowers of two sizes. Insect visitors include various beetles, flies, bees, butterflies and moths, and thy-sanopterous insects.

Dispersal of the seeds takes place by the aid of the wind, the capsule being open above, and acts as a "censer" fruit, the seeds being jerked out by the wind.

Field Mouse Ear is a sandy-soil plant, and aren-ophilous.

The fungal and insect pests are few, and as in C. vulgatum (qu. vide, ibid.).

No other English names have been used for this plant, which is not so well known as the Mouse Ear Chickweed.

It has no medicinal properties, and there is no use to which it has been put so far.

Essential Specific Chars. Stem prostrate, wiry, tufted, leaves linear-lanceolate, downy, petals longer than the calyx, white, bracts membraneous on margin and at tip. April to August.