Weigela japonica
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Kindly sponsored by
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Credits
Tom Christian & Alan Elliott (2019)
Recommended citation
Christian, T. & Elliott, A. (2019), 'Weigela japonica' from the website Trees and Shrubs Online (treesandshrubsonline.
Genus
Synonyms
- Diervilla japonica (Thunb.) DC.
Infraspecifics
Other taxa in genus
- Weigela Aurea Group
- Weigela Bicolor Group
- Weigela coraeensis
- Weigela decora
- Weigela Dwarf Group
- Weigela floribunda
- Weigela florida
- Weigela hortensis
- Weigela maximowiczii
- Weigela middendorffiana
- Weigela Pink-Flowered Group
- Weigela Purpurea Group
- Weigela Red-Flowered Group
- Weigela subsessilis
- Weigela Variegata Group
- Weigela White-Flowered Group
Shrub to 5 m, branches conspicuously hairy when young. Leaves ovate or oblong 4–12 × 2–5 cm, apex caudate or acuminate, base cuneate or rounded, margin shallowly serrate, both surfaces hairy, densely hairy on veins on lower surface, lateral veins 4–6 , petiole 0.5–1.2 cm, hairy. Cymes axillary or terminal on previous year’s growth,1– or 2-flowered. Peduncle < 0.5 cm, hairy or glabrous, bracts and, bracteoles lanceolate, 2–12 mm, caducous. Calyx tube 5-lobed, radially symmetric, linear or awl-shaped, free less than half of length, 0.5–1.2 × c. 0.1 cm, hairy. Corolla funnel-shaped, 2.5–3.5 × 1.5–2.5 cm, abruptly widening from the base, pale yellow or pale brown-purple in bud, red lavender outside, dark red inside, hairy outside. Corolla tube 2–2.7 cm, hairy or becoming glabrous inside, corolla 5-lobed, radially symmetric, ovate or rounded, 0.5–0.7 cm long (c. 20–25% of length of corolla tube). Stamen almost as long as corolla, filaments 0.6–0.8 cm, glabrous; anthers, free, linear ca. 0.5 cm, yellow. Style longer than corolla, 3–4.5 cm long, glabrous, stigma disc-like, c. 3 mm diameter. Fruit cylindrical, slightly curved, 1.7–2.7 cm long, dehiscing from apex, hairy. Seeds ellipsoid, 1.5 mm long, with narrow wings on three sides. Flowers: April to June. Fruits: September to November. (Iwatsuki, K. (ed) 1993).
Distribution Japan Kyushu
Habitat Open areas on hills and moutains. 100–1800 m
Taxonomic note This species is endemic to Japan. There is one supposed record from Korea, Moran 5169 in the US National Herbarium, which is W. subsessilis.
Native to Kyushu in Japan, Weigela japonica was introduced first to the United States in 1892, and soon afterwards to the United Kingdom (Bean 1981). Described by Thunberg in 1780, it is the type species upon which he based the new genus Weigela (tropicos.org).
var. sinica (Rehder) L. H. Bailey
Synonyms
Diervilla japonica var. sinica Rehder
Weigela sinica (Rehder) H. Hara
Shrub to 6 m, branches conspicuously hairy when young. Leaves ovate or ovate elliptic, 5–15 × 3–8 cm, apex caudate or acuminate, base cuneate or rounded, margin shallowly serrate, sparsely hair on upper surface, densely hairy on lower surface, lateral veins 5–6, petiole 0.8–1.2 cm, hairy. Cymes, axillary or terminal on previous year’s growth, 3-flowered. Peduncle < 0.5 cm, hairy or glabrous, bracts and, bracteoles lanceolate, 2–12 mm, caducous. Calyx tube 5-lobed, radially symmetric, linear or awl-shaped, free half of length or more, 1–1.2 × c. 0.1 cm, hairy. Corolla funnel-shaped, 2.5–3.5 × 1.5–2.5 cm, abruptly widening above the caylx lobes, white or red in bud, becoming red outside, dark red inside, sparsely hairy outside. Corolla tube 2–2.7 cm, hairy or becoming glabrous inside, corolla 5-lobed, radially symmetric, ovate or rounded, 0.5–0.7 cm long (c. 20–25% of length of corolla tube). Stamen almost as long as corolla, filaments 0.6–0.8 cm, glabrous; anthers, free, linear ca. 0.5 cm, yellow. Style longer than corolla, 3–4.5 cm long, glabrous, stigma disc-like, c. 3 mm diameter. Fruit cylindrical, slightly curved, 1.7–2.5 cm long, dehiscing from apex, hairy. Seeds ellipsoid, 1.5 mm long, with narrow wings on three sides. Flowers: April to May. Fruits: August to September.
Based on Flora of China account (Yang et al. 2011).
Distribution
- China – Anhui, Fujian, Guangdong, Guangxi, Guizhou, Hubei, Hunan, Jiangxi, Sichuan, Zhejiang.
RHS Hardiness Rating: H5
Taxonomic note Flora of China treats the Chinese populations of this taxon as Weigela japonica var. sinica. The chief difference being that the corolla widens from the base in Japanese populations and from the middle in Chinese populations. This species is not listed as growing int the Korean floras and given the geographic distance between Southern Japan and the Chinese Populations, there may be some merit in treating this taxon as distinct from the type.
Taller than the type, perhaps to 7 m in favourable conditions, but becoming very sparse and gawky if not pruned. Originally introduced by Wilson from western Hupeh in 1908, but it remains uncommon in cultivation (Bean 1981b).
