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 chalky and limestone soils. The habit is grasslike. The stems are erect, numerous, wiry, slender, smooth. The leaves are alternate, narrow, lance-shaped, linear, acute. The flowers are bright - blue, few, in racemose cymes. The sepals are inversely egg-shaped, obscurely 5-veined, hairless, the inner 3 very blunt, entire. The petals are large, distinct. The fruit-stalks are erect. The plant is 1-2 ft. high, flowering in June and July, and is a herbaceous perennial.
The habitat of this plant is dry sandy and chalky places in the south. The habit is as in the last. The stems are numerous, loose, with few, irregular, spreading branches. The leaves are narrow (hence angustifolium), alternate, linear to lance-shaped, fewer and smaller than in L. perenne. The flowers are pale-lilac or blue, few, arranged in a cyme. The sepals are elliptic, pointed, fringed with hairs, the outer egg-shaped, with a long, narrow point, the inner 3-nerved, fringed with hairs. The capsule is downy within. The plant is 1-2 ft. high, flowering in July and August, and is a herbaceous perennial.