This species was described from a flowering specimen collected by Forrest in Yunnan in 1913, but was not introduced on that occasion. The plants treated under the name B. caryopteridifolia in previous editions of this work were raised from seed sent by Forrest during his 1921-3 expedition and were cultivated in the Edinburgh Botanic Garden and in the late Sir Frederick Stern’s garden at Highdown. However, H. F. Comber (Notes Roy. Bot. Gard. Edin., Vol. 18, pp. 230-2, 1934) asserted that these plants were wrongly identified and referred them to B. truncatifolia var. glandulifera (Lévl.) Marquand. In 1947, A. D. Cotton made a new species out of the Highdown plants – B. sterniana – and to it he also referred the plants at Edinburgh. Whether B. sterniana is really distinct from B. caryopteridifolia is debatable (see below). Assuming that it is, then it is doubtful whether the true B. caryopteridifolia is in cultivation. Mr Keenan of the Edinburgh Botanic Garden tells us that some of the plants which he has seen under that name are no more than forms of B. crispa.
B. sterniana Cotton – A deciduous shrub of rounded bushy shape, up to 8 or 10 ft high; young shoots, under-surface of leaves, flower-stalks and calyx, all covered with a thick and at first pure white wool. Leaves opposite; on young barren shoots they are ovate with a heart-shaped base, coarsely and unevenly toothed, 3 to 6 in. long, about half as wide, with golden-brown wool on the upper surface at first, later almost or quite glabrous; stalk 1 to 11⁄2 in. long. On the second-year branchlets the leaves are much smaller and tapered at the base. Flowers fragrant, lavender-coloured, produced on slender panicles up to 3 in. long in spring or early summer from the previous season’s growths. Corolla-tube 1⁄4 in. long, downy, with four small, rounded lobes; calyx half as long as the corolla.
This species, which is probably a native of Yunnan, was described, as explained above, from cultivated plants previously considered to be B. caryopteridifolia. It might appear to be well distinguished from that species in bearing its flowers in spring on the previous season’s wood, whereas B. caryopteridifolia was described as bearing its flowers terminally in early autumn. However, the buddleias of this group shows such variability in their inflorescence, as well as in their leaves, that the unwary botanist might easily make two or even more species out of specimens taken from a single plant. Mr Keenan tells us that at Edinburgh B. sterniana may flower in autumn as well as in spring, and suggests, tentatively, that this species and B. caryopteridifolia may, after all, be one and the same.