Shrubs or small trees, to 8(-10) m, not suckering from roots. Leaves: petiole (2-)4-7(-10) mm; blade with 5-8 secondary veins, oblong-elliptic, ovate-elliptic, ovate to ovate-lanceolate, or subrhombic, 3-11 × 2-5(-7) cm, margins of at least some leaves apically remotely serrate, longest arms of abaxial hairs to 0.6 mm. False-terminal inflorescences 2-5-flowered, 1-4 cm; axillary flowers present on at least some shoots (subtending leaves often reduced). Pedicels 15-50 mm, longer than calyx. Flowers: calyx 4-7 × 3-5 mm; corolla (8-)10-16(-23) mm, tube 3-5 mm, lobes 5(-6), imbricate in bud, slightly reflexed, ovate, oblong-ovate, obovate, or ovate-lanceolate, 11-20 × (3-)5-7(-9) mm; filaments distinct beyond adnation to corolla. Capsules ovoid or ellipsoid, 8-15 × 8-10 mm (broader when 2-3-seeded), gray or grayish yellow stellate-pubescent, dehiscent from distal or proximal end, broadly exposing seed(s); fruit wall 0.4-1 mm thick. 2n = ca. 40.

Flowering May-Jun; fruiting Aug-Oct. Woods; 0-300 m; introduced; Conn., N.Y., Pa.; e Asia.

The ornamental Styrax japonicus has become very locally naturalized in three northeastern states.