Korea Flora: Deciduous shrub. Height 3m. Winter Buds and Stems: Terminal buds globose or conical, apex pointed; 5-6 bud scales, larger than lateral buds, 2-4mm long. Branches thick and much-branched at base, branchlets without thorns. Branches develop thorns. Leaf scars U-shaped or V-shaped. Leaves: Alternate, palmately compound; leaflets (3)4-5, narrowly oblong or narrowly spathulate-oblong, apex acuminate, base cuneate, 4-9cm × 2.5-4.0cm. Upper surface green with fine hairs on midrib; lower surface light green, densely brown-pubescent along veins, margins with fine sharp double serrations. Main and lateral veins with mixture of long straight and curved hairs, or sometimes glabrous. Petiolules 2-7mm long, densely brown-pubescent; petioles 3-8cm long, sparsely brown-pubescent. Flowers: Umbels terminal on new branches, main peduncle 2-4cm long with dense white pubescence. Pedicels 6.5mm long, longer than in E. senticosus. Sepals ovate-acuminate, pubescent; petals ovate-elliptic, reflexed; styles divided into 2. Fruit and Seeds: Ellipsoid, 6mm long, black.

Flowering Period: August-September
Fruiting Period: October
Distribution: Hokkaido to Kyushu (Japan); North Hamgyeong-do, North and South Pyeongan-do, Hwanghae-do, Gangwon-do, Gyeongsangbuk-do and other areas along Baekdudaegan Mountain Range (Korea)

Taxonomic Notes: Jirisan Ogalpi was classified as E. divaricatus var. chiisanensis (Nakai) C. H. Kim and B. Y. Sun (Kim and Sun, 2000), distinguished from E. senticosus by the mixture of long straight and curved hairs on the midrib and lateral veins of leaf undersides. While this hair characteristic and distribution (Jeju Island, Jeollanam-do, Gangwon-do, North and South Hamgyeong-do) are mentioned as unique features, it is now considered a synonym of E. senticosus as part of individual variation within the species.