Korea Flora: Deciduous tree. Height 25m. Winter Buds and Stems: Single terminal bud, semicircular to conical, apex rounded or slightly pointed. 2-3 bud scales; terminal buds larger than lateral buds, winter buds 5-9mm long. Branches with numerous thorns. Leaf scars large, V-shaped. Leaves: Alternate, orbicular, palmately divided into 5-7(9) segments; segments ovate or elliptic, apex acuminate, base cordate or subcordate, palmately veined, 10-30 × 10-30cm. Upper surface glabrous, lower surface with or without dense hairs in vein axils, margins serrate. Petiole 7-20(50)cm long. Flowers: Perfect (hermaphroditic), umbels terminal on new branches, glabrous or slightly pubescent; main axis short, 8-15cm long, with about 10 spreading lateral branches that rebranch to form 10+ inflorescences. Flowers 5mm in diameter, yellowish-green; bracts 1-2cm long, caducous; pedicels 7-19mm long; petals, sepals, and stamens 5 each. Ovary inferior with bifid style. Fruit and Seeds: Subglobose, 4mm × 6mm; drupes bluish-black with 2(3) seeds. Seeds semicircular, flattened, 4-5mm × 3mm.

Sporophyte Chromosome Number: 48
Flowering Period: Early August
Fruiting Period: Late September to mid-October
Distribution: Throughout China, Far Eastern Russia and Southern Kuril Islands, Hokkaido to Kyushu (Japan); throughout Korea

Ecological Characteristics: Found as scattered individuals rather than in dense populations. Grows in moderately lit areas as a light-demanding species. Very shade-tolerant when young, growing well in dark forest understory; strong light can cause leaf desiccation and poor growth. Thrives in coastal areas and gentle slopes. Seeds dispersed by birds, leading to scattered rather than clustered growth. Initial growth very slow with dormancy periods. Root system characteristically deep.

Taxonomic Notes: Shows extreme leaf variation; previously reported varieties (var. pinnatifidus, var. pilosus) and cultivars are now considered synonyms of K. septemlobus (Chang et al., 2003).