Korea Flora: Shrub up to 10m tall. Winter buds sharp-pointed, 2-3 cm long with 2 pairs of scales. Terminal bud lacking, 2 pseudoterminal buds, leaf scars V or U shape. Branchlets hairless, brown-red.  Leaves deciduous, opposite, almost circular . 5-7cm long and 6-8(9)cm wide, and. usually 5-7(9) lobes. Lobes broadly triangular. pale green beneath and downly in spring becoming hairless, red in autum. Petiole 3-5 cm long.  Inflorescence terminal, corymbose, 20-flowered, andromonoecious with half of female flowers; peduncles 2.5-4 cm. peduncle 2.5-4cm long, Sepals 5, red, Petals 5, yellowish white. Stamens 8, ovary glabrous. Fruit including wing 10 mm long, wing narrowly obovate.

Flowering May
Fruting mid to late October
Distribution Honshu to Kyushu (Japan); Jeju and Jeolanamdo to Jeloabukdo.

Taxonomic notes: This species is naturally distributed only in southeastern Korea (Jeollanam-do & Jeollabuk-do). It grows in the valleys due to the characteristics of seed germination and leaves of this taxon are somewhat larger than those of Japanese A. palmatum. Most of this maple trees cultivated for domestic ornamental purposes are Acer palmatum var. amoenum (Carrier) Ohwi], which has rather large fruit, a large leaf size, and a wide variety of cultivars. Since the quantity of chloroplasts in A. palmatum var. amoeum is fewer than that of A. palmatum var. palmatum in the leaves, there are many cultivars with anthocyanin (cyanide compounds) exposed from spring to red.  Seeds of var. palmatum are germinated by wet-stratification treatment and due to these characteristics this taxon grows in the valleys. On the other hand, var. amoenum is distributed in ridges in Japanese native areas. These two varieties are considered to be continuous variations in terms of morphology in both countries, but it is because of differences in ecology and habitat that the var. amoenum is recognized only as a variety.

Japan Flora: Tree, with the young buds loosely yellowish brown pubescent, soon glabrous; leaves chartaceous, suborbicular, 4-7 cm. wide, cordate-truncate or subcordate at base, glabrous, palmately 5- to 7-lobed often to the middle, the lobes lanceolate to broadly so, acuminate, rather prominently duplicate-serrate, the petioles glabrous, slender, 3-5 cm. long, reddish; inflorescence a glabrous, pendulous, more than ]0-flowered compound corymb, the slender peduncles 3-4 cm. long; flowers dark red, 4-6 mm. across; sepals oblanceolate, about 3 mm. long, loosely brown-pubescent at apex; ovary glabrous or with few rusty brown soft hairs; samaras glabrous, ascending or spreading, the wing about 1.5 cm. long.  Apr.-May. Woods and thickets in lowlands and mountains;

Honshu, Shikoku, Kyushu; very common and variable, with numerous cultivars grown in gardens. Korea.