Description from Flora of China
Salix purpurea Linnaeus var. japonica Nakai.
Shrubs. Branchlets russet or purplish red, slender, glabrous. Buds purplish red, rarely yellowish brown, ovoid, longer than petiole, at first pilose at apex, glabrescent, shiny. Leaves opposite, rarely alternate, thinly leathery; petiole 2-5 mm; leaf blade oblanceolate or linear-oblanceolate, 5-10 × 0.6-1.5 cm, glabrous, abaxially pale, adaxially green, base cuneate, margin entire proximally, serrulate distally, apex acuminate or acute; midvein yellowish; lateral veins dense, curved. Flowering precocious. Catkins opposite, rarely alternate, thinly terete, 2-3 cm × 3-4 mm, sessile; bracts black, obovate or long obovate, ca. 1.5 mm, villous, apex obtuse. Male flower: stamens 2, connate throughout, rarely only filaments united, glabrous; anthers purplish red, globose, 4-loculed, rarely 2-loculed. Female flower: ovary ovoid, densely grayish white tomentose, sessile; style short to absent; stigma entire or 2-lobed. Fl. May, fr. Jun.
Similar to Salix integra but young branchlets purplish red; leaf blade longer and narrower; bracts black. Similar also to the mainly European species S. purpurea Linnaeus, but young branchlets, winter buds, and petioles purplish red.
Cultivated in gardens. E Liaoning [Japan, Korea]