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.
The character as above. A genus of nearly 200 species, dispersed nearly all over the world. The hardy species are not numerous, and by no means so showy as many of the tenderer kinds from the Cape of Good Hope. Name from much, and milk. This is variously explained.
1. P. vulgaris. Common Milkwort. - An indigenous and very variable species according to soil and situation. Under cultivation the numerous slender prostrate or erect stems usually grow about a foot long. Leaves small, oblong or lanceolate, glabrous. Flowers about 4 to 6 lines long, in terminal racemes, blue, lilac, purple, pink, or white.