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.
Tall climbing deciduous shrubs with imparipinnate leaves and terminal pendulous racemes of bluish flowers. The two upper teeth of the calyx short and subconnate, the inferior longer. Standard large. Stamens diadelphous, or the vexillary united with the others at the middle. Pod elongated, twisted; valves scarcely coriaceous, dehiscent; seeds reniform, estro-phiolate. About four or five species are known, one from North America and the rest from China and Japan. So named in honour of an American botanist. Some of the species were formerly erroneously referred to the genus Glycine.
1. W. Sinensis (fig. 70), syn. W. consequana. - Nothing can exceed the beauty of this magnificent climbing shrub when in full flower, towards the end of April or in the beginning of May, before the leaves are fully developed. This is the only species common in gardens, and by far the handsomest known. In the South of England it attains great perfection on a trellis or pillar, but in the North it requires the protection of a wall. There is a white-flowered variety, but the ordinary purplish-lilac one is the better of the two. A native of China.
Fig. 70. Wistaria Sinensis. (1/4 nat. size.)
2. W. frutescens. - This is, perhaps, hardier than the preceding, but, although introduced many years previous to that, it is still far less generally cultivated, on account of its inferiority as an ornamental plant. It is altogether a smaller species, with darker flowers of a violet tinge; but as it does not blossom till Autumn, both should be grown where there is space. A variety called magnifica exceeds the old form in beauty. A native of North America.
3. W. brachybotrys. - A more erect shrub with slender sar-mentose branches and ovate or cordate leaflets, silvery when young. The flowers are larger and of deeper violet, in closer shorter racemes than in the above species, and they are produced in Spring with the leaves. A native of Japan.
W. multijuga is a native of Japan, of quite recent introduction.