(Buddleja alternifolia)
Buddleja alternifolia, known as alternate-leaved butterfly-bush, is a species of flowering plant in the figwort family, which is endemic to Gansu, China. A substantial deciduous shrub growing to 4 metres (13 ft) tall and wide, it bears grey-green leaves and graceful pendent racemes of scented lilac flowers in summer. B. alternifolia is a vigorous deciduous shrub reaching 5 m (16 ft) tall with long, slender, pendulous stems. The leaves are alternate, entire, and lanceolate, 4–10 cm long by 0.6–1 cm wide, glabrous and dark green above. The inflorescences of the plants in cultivation are bright lilac-purple, and comprise flowers so densely crowded in clusters along the branch as to often obscure it. However, specimens from the Tsangpo valley in Tibet originally named B. tsetangensis by Marquand have creamy flowers. Flowering occurs in early summer; the flowers are fragrant, but less so than other buddlejas. 2n = 38. In its native territory it grows along river banks in thickets at elevations of 1,500–4,000 m (4,900–13,100 ft).