This section is from the book "British Wild Flowers - In Their Natural Haunts Vol5-6", by A. R. Horwood. Also available from Amazon: A British Wild Flowers In Their Natural Haunts.
There is no record of this in beds containing fossil remains of recent plants. It is distributed throughout temperate Europe, Asia as far as the Himalayas, North Africa. This little plant is known in every district in Great Britain except Cardigan, Mid Lancashire, Stirling, N. Hebrides, Orkneys, ranging from the west of England to the Orkneys and throughout the south. It is found also in Ireland and the Channel Islands.
Vernal Whitlow Grass, as the name implies, is a spring flower which adorns our mud walls or stone walls and roofs in the majority of English and Scottish counties. It is also found on mole-heaps and other dry spots which are raised above the general level at a distance from houses in the open fields. It is a xerophyte, and occurs also on gravel-walks, cinder-paths, terraces, in the cracks of walls and similar spots.
The habitat of this plant is associated with its habit. For its leaves, which are lance-shaped, acute, and are hairy and narrowed below, are arranged in a regular rosette at the base of the plant, which in its usually exposed position help to prevent it from being uprooted. The short aerial stem is a scape, leafless, and bears few flowers. Many of these little plants grow together like little mats scattered over the surface.
The style is not marked, the stigma pin-headed. There are numerous seeds. When it is wet and at night the flowers hang down.
This is a diminutive plant, the scape not being more than 3-5 in. high. The first Latin name was given in allusion to its early flowering, viz. March to April. It is an annual.
Between the base of the short and long stamens, which are adjacent, there are 4 small, fleshy, green honey-glands. Anthers and stigma ripen together. The longer stamens reach the level of the stigma, and closely surround it, opening towards it and dusting it with pollen, and the shortest stamens also, but they are below it. The insect's head is placed between the stigma and shorter stamens, and is covered with pollen, and in transferring it to another flower cross-pollination follows. Cross-pollination is brought about by the short stamens, and the four longer regularly cause self-pollination, which is effective. The flowers are not conspicuous, and insects seldom visit it. The visitors are the Honey-bee, Andrena parvula, Halictus.
Photo Flatters & Garnett - Vernal Whitlow Grass (Erophila verna, E. Meyer)
The plant is dispersed by its own agency. The pods when dry become tense, and disperse the numerous small seeds to no great distance.
Vernal Grass is a sand-loving plant, and requires a sand soil with no humus.
A beetle, Ceuthorhynchus hirtulus, causes galls, but there are no other insect pests.
Erophila is derived from er, spring, phileo, I love; and verna is Latin for vernal or spring.
The English names are Faverel, Whitlow Grass, Nailwort. White Blow. The flowers droop at night and in wet weather. In Sweden they sow their rye when the Whitlow Grass is in flower.
Essential Specific Characters: 28. Erophila verna, E. Meyer. - Stem (flowering) leafless, leaves radical, lanceolate, acute, dentate, hairy, petals white, deeply cloven, capsule a compressed oval pouch, many-seeded.