A deciduous shrub, of bushy habit, 6 to 12 ft high, more in diameter; the branchlets covered with a white or tawny, loose felt. Leaves lanceolate, 2 to 5 in. long, 3⁄4 to 13⁄4 in. wide; slightly heart-shaped or cut nearly square at the base, tapering thence to the point, coarsely and angularly toothed, covered above, and more so below, with a whitish or tawny down; stalk 1⁄4 to 1 in. long. Flowers fragrant, produced in June or later in a terminal panicle 3 in. high and 2 in. wide, formed of axillary whorls. Corolla lilac-coloured; the tube 1⁄3 in. long, downy outside; the four-lobed limb about as much in diameter, white near the orifice of the tube. Calyx with erect, ovate lobes, woolly like the stem. Bot. Mag., t. 4793.
Native of Afghanistan and the Himalaya, where it is occasionally a small tree; a similar but not identical plant is found in W. China. At Kew, a plant raised from seed sent home by Dr Aitchison from Afghanistan in 1879 proved perfectly hardy and grew there for more than thirty years without protection. This plant no longer exists, but later introductions have proved as hardy. It is seen at its best when grown on a wall, where it will flower continuously from June to the first frosts if pruned back in spring. It was given an Award of Merit in 1961. This species appeared in previous editions as B. paniculata Wall., which is probably not in cultivation.