Shrub to 5 m, branches glabrous. Leaves broadly elliptic to obovate-elliptic, 8–15 x 4–10 cm, apex caudate or acuminate, margin shallowly serrate, glabrous or occasionally with hairs at base of veins on lower leaf surface, lateral veins 4–7 pairs, petiole 1–1.5 cm, glabrous. Cymes, axillary or terminal on previous year’s growth, 2- or 3-flowered. Peduncle to 10 mm, glabrous or sparsely hairy, bacts and, bracteoles linear, narrowly lanceolate, 2–12 mm, both caducous. Calyx tube 5-lobed, radially symmetric, linear, free more than half of length, 0.8–2 x 0.1–0.2 cm, glabrous or with a few scattered hairs. Corolla funnel–shaped, 2.5–4 x 2–3 cm, abruptly widening above caylx lobes, white in bud becoming light red outside, deep pink inside, glabrous outside. Corolla tube 1.5–2 cm, hairy inside, upper part of tube distinctly expanded, corolla 5-lobed, radially symmetric, ovate, 0.8–1.2 cm long (c. 30% of length of corolla tube). Stamen shorter than corolla, filaments 0.7–1.3 cm, glabrous; anthers, free, linear 0.5–0.7 cm, yellow. Style nearly as long as corolla, 2.5–3 cm, glabrous, stigma disc-like, c. 4 mm diameter. Fruit cylindrical 2–3 cm long, dehiscing from apex, glabrous. Seeds ovoid, 1.5 mm long, with narrow wings on three sides. Flowers: May to June. (Iwatsuki (ed) 1993).
Distribution Japan Honshu
USDA Hardiness Zone 5-7
RHS Hardiness Rating H5
Taxonomic note The Japanese Flora distinguishes two forms, based on consistency of flower colour, and one variety, based on having a smaller corolla and fragrant flowers. forma alba (Voss) Rehder with white flowers and forma rubriflora Momiyama with flowers that are rose-red and darker red. var. fragrans (Ohwi) Hara has a smaller corolla only 1.1–1.5 cm long and is fragrant. This variety is endemic on two of the Izu Islands, Miyake-jima and Hachijo-jima.
While the specific epithet suggests some affinity with the Korean peninsula, Weigela coraeensis is in fact only native to Honshu, Japan. It has long been cultivated in Japan and is now naturalised outside its native range on Honshu, as well as in parts of Shikoku and Kyushu (Iwatsuki (ed) 1993). It was introduced to Europe in the mid-19th century, although the details are sketchy, and it is as likely that the first introductions were from cultivated stock as from wild populations (Bean 1981b).