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.
The habitat of this plant is fields, banks, dry gravelly places, cornfields, limestone rocks. The habit is prostrate, then ascending, with branches downy, stems with turned-back hairs, slender, and bearing numerous leaves. The leaves are narrow at the base, with the margin rolled back, an adaptation to dry conditions, egg-shaped, toothed, with a long point. The flowers are bluish-purple, with white spots, in simple whorls, 5-6, with leaflike bracts, with bracteoles not so long as the flower-stalk. The tube is closed with hairs, the calyx swollen below, 2-lipped. The plant is short, 4-10 in. high, and is in bloom from June to September, being a herbaceous annual or biennial.
The habitat of this plant is grassy places. The habit is similar to the common form, but spreading, prostrate below, and from this it differs in having the leaves deeply divided nearly to the base. The flowers are creamy-white, or in rare cases blue. The teeth of the calyx are fringed with hairs. The height is 2-9 in., and it is in flower in July and August, the plant being a herbaceous perennial.
The habitat of this plant is dry fields and grassy places. The habit is erect, tall, with glandular hairs above, the stem square, with few leaves, wrinkled, the radical leaves egg-shaped, oblong, heart-shaped below, on long stalks, blunt, scalloped, toothed, the upper stalkless, small, lance-shaped. The large flowers are purple, or bluish-violet, smooth inside, the corolla sticky, three times as long as the calyx. The bracts are long-pointed, heart-shaped below. The plant is 2-4 ft. in height, being handsome, and flowers from June to August, being a herbaceous perennial, and is well worth a place in the garden.
The habitat of this plant is fields, roadsides, calcareous places, woods, hedges, on dry soil. The habit is erect. The rootstock bears stolons, the stem is thick, branched, and covered with a felt of white down, or densely silky. The lower leaves are tufted, egg-shaped, oblong, heart-shaped, wrinkled, on long stalks, the upper stalkless, lance-shaped, scalloped, toothed. The flowers are in stout spikes, rose-purple, the corolla downy, the upper lip spotted, the flowers in interrupted whorls below, on short stalks. The calyx is softly hairy, the upper lip longest. The bracts equal the calyx. The plant is 1-3 ft. in height. Flowers are to be found in July and August. The plant is a herbaceous biennial.
The habitat of this plant is stony fields and calcareous places. The habit is erect, the stem branched from below, and the leaves numerous, deeply divided nearly to the base, or 3-lobed, the lobes oblong or divided, or blunt, the veins prominent below. The flowers, in whorls in the axils, are rose-purple, the calyx swollen below, glandular, netted in fruit. The lower lip of the corolla is spotted red and white. The nutlets are pitted. The stem is 4-12 in. in height. July to September is the flowering season. The plant is a herbaceous perennial.