A deciduous shrub of very vigorous growth, or a small tree from 10 to 20 ft high, lax and widely branched, making pendulous shoots several feet long in one season. Young growths ribbed, at first furnished with minute scurfy down, soon becoming glabrous. Leaves alternate, entire, lanceolate, pointed, wedge-shaped at the base; 11⁄2 to 4 in. long, 1⁄4 to 1⁄2 in. wide; dull dark green and glabrous above, glaucous or minutely scurfy beneath; stalk about 1⁄8 in. long. Flowers produced in June from the joints of the previous year's growth, densely crowded in clusters about 1 in. wide, often completely hiding the branch. Corolla bright lilac-purple, tubular at the base, dividing at the mouth into four rounded lobes and about 3⁄16 in. wide there. Calyx tubular, 1⁄8 in. long, four-lobed, glaucous and scurfy like the flower-stalk, which is about as long as the calyx. Bot. Mag., t. 9085.
Native of Kansu, China, described and named by Maximowicz in 1880, but introduced by W. Purdom and Reginald Farrer about 1915. This species is remarkably distinct from other cultivated buddleias in its alternate leaves. It is also singularly beautiful, flowering freely when a few years old and growing with great vigour. The flowers are fragrant, although not so much so as in some of the buddleias. I have seen no finer or handsomer specimen than one in the Royal Horticultural Society's Garden at Wisley, where it is a small tree. In the chalk garden at Highdown, near Worthing, it was, in May 1930, 16 ft high and wide, but, owing to the warmer climate, of looser, more diffuse branching than at Wisley. Farrer writes of it as seen in Kansu: 'a gracious, small-leaved, weeping willow when it is not in flower and a sheer waterfall of soft purple when it is'. I saw the Wisley tree in flower a few years ago and appreciated the aptitude of these comparisons. Whenever possible, it should be trained up into tree form. It likes a sunny position and a good loamy soil; easily increased by cuttings or by the root suckers it occasionally develops. It is one of the species that bears its flowers on wood made during the previous summer and should therefore not be spring-pruned.
The two plants referred to above still thrive (1966); the late Sir Frederick Stern told us that his was raised from the original seed (Farrer 100), which makes it more than half a century old.
cv. 'Argentea'. – Leaves with appressed silky hairs, which give them a silvery sheen.