Buddleja davidii var. alba Rehder & E. H. Wilson; B. davidii var. glabrescens Gagnepain; B. davidii var. magnifica (E. H. Wilson) Rehder & E. H. Wilson; B. davidii var. nanhoensis (Chittenden) Rehder; B. davidii var. superba (Veitch) Rehder & E. H. Wilson; B. davidii var. veitchiana (Veitch) Rehder & Bailey; B. davidii var. wilsonii (E. H. Wilson) Rehder & E. H. Wilson; B. shaanxiensis Z. Y. Zhang; B. shimidzuana Nakai; B. striata Z. Y. Zhang; B. striata var. zhouquensis Z. Y. Zhang; B. variabilis Hemsley; B. variabilis var. magnifica E. H. Wilson; B. variabilis var. nanhoensis Chittenden; B. variabilis var. prostrata C. K. Schneider; B. variabilis var. superba Veitch; B. variabilis var. veitchiana Veitch; B. variabilis var. wilsonii E. H. Wilson.
Shrubs 0.5--5 m tall; young branchlets, leaves abaxially, petioles, and inflorescences white tomentose or pubescent with stellate hairs. Branchlets nearly 4-angled. Stipules often present, suborbicular to ovate, 1--6 mm. Petiole 1--5 mm; leaf blade narrowly ovate, narrowly elliptic, or very narrowly ovate, 4--20 X 0.3--7.5 cm, adaxially dark green and glabrous or subglabrous, base cuneate, margin serrate, apex acuminate, lateral veins 9--14 pairs. Inflorescences terminal, seemingly racemose or thyrsoid cymes, 4--30 X 2--5 cm; lower bracts leaflike, others small and linear. Calyx campanulate, 2--3.5 mm, outside stellate pubescent to glabrous; lobes narrowly triangular, 0.5--2 mm. Corolla violet to dark purple, sometimes white, with an orange-yellow throat, 0.8--1.4 cm, outside glabrous or stellate pubescent and/or with glandular hairs; tube narrowly cylindrical or subcylindrical, 6--11.5 X 1--1.5 mm, inside pilose except at base; lobes suborbicular, 1.5--3 X 1.5--3 mm, outside glabrous. Stamens inserted at middle to near base of corolla tube; anthers oblong, 0.8--1.2 mm. Ovary ovoid, 1.2--2 X 0.8--1.1 mm, glabrous to minutely pubescent, sometimes with glandular hairs. Style 0.5--1.5 mm; stigma clavate. Capsules brown, narrowly ellipsoid to narrowly ovoid, 5--9 X 1.5--2 mm, glabrous or sparsely stellate pubescent. Seeds ellipsoid, 2--4 X ca. 0.5 mm, long winged at both ends. Fl. May-Oct.
Thickets on mountain slopes, side of draws in mountains; 800--3000 m. Gansu, Guangdong, Guangxi, Guizhou, Hubei, Hunan, Jiangsu, Jiangxi, Shaanxi, Sichuan, Xizang, Yunnan, Zhejiang [Japan (most probably introduced)].
Medicinal; ornamental.
Buddleja davidii Franchet X B. fallowiana I. B. Balfour & W. W. Smith has been reported from Yunnan (Leeuwenberg, Meded. Landbouwhogeschool 79(6): 149. 1979). This hybrid
has the following characteristics: Shrubs. Branchlets terete, densely stellate tomentose. Leaves subsessile to petiole 6 mm; leaf blade ovate to narrowly elliptic, 4--13 X 1--6.5 cm, both
surfaces densely stellate tomentose to adaxially glabrescent, base cuneate to decurrent, margin crenate-serrate, apex acuminate, acute, or obtuse, venation inconspicuous.
Inflorescences terminal, thyrsoid, 5--15 X 2--3 cm. Calyx campanulate, 3.5--5 mm, inside densely stellate tomentose. Corolla violet to lilac, with an orange-yellow throat, outside densely
stellate tomentose and with glandular hairs, tube ca. 9 mm; lobes orbicular, 1--3 X 1--3 mm. Stamens inserted above middle of corolla tube; anthers oblong. Ovary oblong, stellate
tomentose. Fl. May-Oct.
