This section is from the book "British Wild Flowers - In Their Natural Haunts Vol2-4", by A. R. Horwood. Also available from Amazon: A British Wild Flowers In Their Natural Haunts.
Venus's Looking Glass is more common in the south and east, because it is best suited by a chalky or calcareous soil, and this type of rock soil is confined to those districts. It grows amid the corn in parts of the fields where the stalks are not close, and hides at the foot of the corn like Lamb's Lettuce, with which at a cursory glance it might be confused.
It is a weak straggling weed, with a simple or branched stem, branched at the base, and erect. The leaves are oblong, with rounded teeth, the radical leaves stalked, egg-shaped or spoon-shaped, and the stem-leaves are blunt.
The flowers are in the axils, nearly stalkless, lilac, few, terminal, or single. The calyx exceeds the blue corolla, which is open, and the segments are long. The corolla is wheel-shaped. The capsule is triangular and long.
Venus's Looking Glass is about 1 ft. in height. Flowers are found from May till August. It is an annual plant, and increased by seeds.
The whole flower is like Campanula, but the ovary is very long, and narrower. The corolla-limb is peculiar, the corolla regular, wheel-shaped, with the anthers, which mature first, free, the corolla-lobes deep. The pollen is accumulated on the hairs of the style. Insects alight on them and carry away the pollen. At night the corolla folds up lengthwise, and the five lobes become dusted with pollen. When ripe the three stigmas lengthen, and insects deposit pollen on them from another flower, whilst at night the pollen on the corolla touches the stigmas.
In Specularia perfoliata the flowers are cleistogamic. In this species the flower grows hidden amongst the corn, and insects cannot find it, so that self-pollination is inevitable.
Photo. A. R. Horwood - Venus's Looking Glass (Legousia hybrida, Delarbre)
The capsule is long and narrow and ribbed, and the seeds may be partly dispersed like those of the censer fruits by aid of the wind.
This plant is largely a lime plant growing on a lime soil, but will also subsist on a dry sand soil. The Oolites are a specially favourite formation of this plant.
Legousia is from Legous, in honour of an early botanist, and the second Latin name refers to the twofold colour of the corolla, blue inside, lilac outside.
This plant is called Venus's or Our Lady's Looking Glass and Corn Violet.
Essential Specific Characters: 189. Legousia hybrida, Delarbre. - Stem wiry, terete, sub-simple, glabrous, angular, leaves sinuate, radical leaves stalked, stem-leaves sessile, flowers few, solitary, lilac-blue, sessile, in the axils, corolla rotate, shorter than the rough calyx, capsule triangular.