Philadelphus tenuifolius Rupr. & Maxim.

Shrub 2-2.5 m. Leaves oblong, 4-8 cm long. Flowers white, 2-3 cm diam., 3-11 in each inflorescence. Very ornamental. Cold resistant, shade tolerant. Z 5. New.

Shrubs 1-3 m tall. Branchlets of previous year gray-brown, those of current year brownish, pubescent. Petiole 3-8 mm; leaf blade ovate or ovate-elliptic, 3-11 × 2-6 cm, abaxially usually villous along veins, adaxially sparsely villous, base subrounded or broadly cuneate, margin remotely serrate or dentate, apex acute or acuminate; leaf blade on flowering shoots ovate or ovate-elliptic, 3-6 × 2-3 cm, base rounded or obtuse, margin subentire, apex acuminate. Racemes 3-7(-9)-flowered; rachis 3-5 cm, sparsely hairy; pedicels 3-10 cm. Calyx tube yellowish green when dry, sparsely villous; lobes ovate, ca. 5 mm. Corolla discoid; petals white, ovate-oblong or suborbicular, 1-1.5 × 0.6-1.3 cm, apex rounded, slightly 2-lobed. Stamens 20-30, longest ones ca. 1 cm. Disc glabrous. Style slightly divided, slender, glabrous; stigmas mallet-shaped, ca. 1.5 mm, shorter than anthers. Capsule obconical, 4-6 × 4-5 mm. Seeds 2.5-3 mm, shortly tailed. Fl. Jun-Jul, fr. Aug-Sep.

Far East (Amur River basin), northern China and Korea. In mixed forests.

Heilongjiang, Jilin, Liaoning, ?Nei Mongol [Korea, SE Russia].

Thickets; 100-900 m.