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 species is dry rocks, cliffs, etc. The plant has more or less the rosette habit. The rootstock is woody. The stem is sticky at or below the nodes, smooth between, simple. The radical leaves are lance-shaped, tufted, stalkless. The stem-leaves are small, narrow, stalkless. The leaves are smooth, with a woolly margin below. The flowers are large, rose colour, in narrow panicle-like cymes or racemes, whorled, few. The calyx is purple, membranous, tubular, with short acute teeth, not inflated. The petals are notched, crowned, nearly entire, inversely ovate. The scales are short. The capsule is 5-celled at first, broadly ovoid, the carpophore or stalk half the length. The seeds are kidney-shaped, very small, with sharp points. The plant is 12-15 in high, flowering in June and July, and is a herbaceous perennial.
The habitat of this plant is alpine moors and ravines, mountains. The habit is tufted. The rootstock is short, much-branched. The stem is not clammy, simple, hairless. The leaves are crowded, narrow, linear to lance-shaped, smooth, fringed with hairs at the base. The flowers are small, in compact cymes, slender, rosy, the petals 2-lobed, hardly crowned, with 2 small tubercles, the flowers shortly-stalked. The calyx has faint nerves and rounded teeth. The carpophore is half the length of the capsule. The capsule is 5-celled when young, egg-shaped, the stalk half as long. The seeds are kidney-shaped, very small, with blunt tubercles. The plant is 3-8 in. high, flowering in June and July, and is a herbaceous perennial.
The habitat of this plant is walls and thatched roofs, dry places. The plant has more or less the rosette habit. The stems are slender, branched below. The radical leaves are stalked, elliptic to oblong, acute. The stem-leaves are few, stalk-less, ovate, linear. The flowers are white or pinkish-white, 3-8 in an umbel, few, erect, on downy sticky stalks. The ultimate flower-stalks are erect in flower, turned back in fruit, then erect again. The bracts are small, membranous. The sepals are white, with membranous margins, blunt. The petals are a little longer than the sepals. There are frequently 3 stamens and 3 styles. The capsule is twice as long as the sepals. The plant is 1-5 in. high, flowering in April and May, and is a herbaceous annual.
The habitat of this plant is alpine and subalpine rocks. The habit is prostrate or ascending. The plant is hairy all round. The stems are branched below, then simple, long. The plant has the habit of C. arvense, but broader leaves, fewer, larger flowers, and a capsule nearly twice as long as the sepals, on a spreading flower-stalk. The leaves are ovate-oblong, lance-shaped, blunt, downy, covered with long, simple, white hairs. The flowers are white, large, few, in a forked panicle, not so long as the stalks. The sepals are blunt, with membranous margins. The bracts are herbaceous, with more or less membranous margins. The fruit-stalks are obliquely spreading. The capsule is nearly cylindrical, curved at the end. The seeds are tubercled, small. The plant is 3-6 in. high, flowering from June to August, and is a herbaceous perennial.