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.
Calyx-tube slender, scarcely produced above the seod-vessel; limb 4-lobed, deciduous. Petals 4, often 2-lobed. Stamens 8, alternately smaller. Capsule 4-celled, dehiscing between the cells; seeds numerous, with a tuft of silky hairs at the tip. There are upwards of fifty species in the temperate and frigid regions of both hemispheres. The common native species E, hir-siitum, popularly known under the name of Codlins-and-Cream, is found by the side of almost every ditch and water-course. It is a coarse growing plant, often 6 or 7 feet high, but its large rosy flowers are very striking and conspicuous towards the end of Summer. The name is derived from upon, a pod, in reference to the flower being seated upon the pod.
1. E. angustifolium (fig. 104). Rose Bay or French Willow. - The only species worth cultivating. It is a native plant, with bright rosy-purple flowers, produced in Summer. The form usually seen in cultivation differs slightly from the ordinary wild one in its larger flowers and shorter seed-vessels. There is also a good white variety.
Fig. 104. Epilobium angustifolium. (1/4 nat. size.)