Shrub 1–3 m; bushy habit. Branchlets terrete to subquadrangular, glabrous or minutely stellate-tomentose, with glandular hairs when young, later glabrescent. Leaves opposite, shortly petiolate. Leaf blade ovate to narrowly elliptic, 7–30 × 1.5–10 cm, upper surface glabrous or with scattered stellate and/or glandular hairs, underside minutely white-tomentose and with some glandular hairs , base cuneate to rounded, apex acuminate. Margin crenate-serrate to sometimes sub-entire. Inflorescence terminal, paniculate, up to 12–30 × 2–5 cm. Flowers shortly pedicellate, honey-scented. Corolla four-lobed, 6–8 mm diameter, pale lilac to mauve with a yellow or orange throat. Corolla tube 5–8 mm long, outside glabrous or mostly so in the upper half, inside pilose with simple hairs in the throat. Stamens inserted just below corolla mouth, filaments very short. Pistil glabrous 3.2–3.7 mm, stigma clavate, ovary ovoid and laterally compressed, abruptly narrowed into the included style. Flowering early summer onwards, followed by ellipsoid dehiscent capsule 3–4 × 1.5–2 mm. Seeds brown, 2 × 0.5 mm, spindle-shaped, ellipsoid grain with slender wings at both ends. (Leeuwenberg 1979; Li & Leeuwenberg 1996).
Distribution China Guizhou, Henan, Hubei, Hunan, Shaanxi, Sichuan, Yunnan.
Habitat Open woodland, forest edges, stream banks, 500–3000 m asl.
USDA Hardiness Zone 6-9
RHS Hardiness Rating H6
Conservation status Not evaluated (NE)
Buddleja albiflora is a Chinese Buddleja superficially very similar to B. davidi, but it is significantly less common in gardens despite having been introduced by Wilson in 1901 (Bean 1976). There have been occasional later collections: for example Stuart (2006) mentions Lancaster 1577 from Sichuan in 1981, presumably gathered during the SBEC expedition. Although very hardy, it is unlike B.davidi in being more or less fully deciduous rather than semi-evergreen. The epithet is something of a misnomer, as most plants have pale lilac to medium mauve flowers; the inflorescences can be very long, although the individual flowers are both smaller and less dense on the panicle than in B. davidii. B. albiflora can also be distinguished from B.davidi and B. myriantha by the pigmented and more rounded stems. There are also notable differences in the flowers: unlike B. davidi, the mouth of the flower contains numerous simple hairs; the exterior of the corolla tube is mostly glabrous, whereas that of B. myriantha is tomentose.
Buddleja × alata Rehder & Wilson herbarium specimens were considered a perfect intermediate of B. nivea and B. albiflora by Leeuwenberg (1979), and hence may be a natural hybrid of the two species, although this remains unconfirmed by any later study; no example is currently known in cultivation. In gardens, B. albiflora hybridises readily with several species, including B.davidii, but none are in commerce.