This section is from the book "Handbook Of Hardy Trees, Shrubs, And Herbaceous Plants", by W. Botting Hemsley. Also available from Amazon: Handbook of hardy trees, shrubs, and herbaceous plants.
Perennial herbs. Leaves entire. Calyx - limb feathery. Corolla - tube slender, flattened longitudinally, divided and spurred at the base. Stamen 1. Fruit membranous. There are ten species, in the north temperate regions of the Old World. Named from a spur, and a flower.
1. C. ruber (fig. 120). - An old inhabitant of cottage gardens. A glabrous plant about 2 or 3 feet high, with smooth leathery lanceolate or ovate leaves and crimson flowers in dense terminal cymes. The flowers are red, crimson or white in different varieties. A plant of wide distribution, and naturalised in some parts of England.
Fig. 120. Centranthus ruber. (1/6 nat. size.)
2. C. macrosiphon. - An annual of compact habit, glaucous foliage, and rosy carmine flowers rather larger than in the preceding. A native of Spain. There is a white-flowered and a very dwarf variety in cultivation. Fedia Cornucopiae is an allied North African annual with lilac-rose or carmine flowers.