Korea Flora: Deciduous tree. Height 10m, usually shrub-like. Winter buds and branchlets: Winter buds with or without hair. Branch tips have one terminal bud, large and ovoid, pointed, with 2-4 bud scales. Lateral buds opposite, smaller than terminal bud, 5-13mm long. Branchlets grayish-brown, hairless. Leaf scars large, semi-circular or heart-shaped. Leaves opposite, odd-pinnate compound. 5-7 leaflets, ovate, broadly ovate, broadly lanceolate, or lanceolate. As a hexaploid plant, leaf variation is extreme. Apex acuminate, base cuneate, size 6-15cm × 3-7cm. Upper surface green and hairless, lower surface grayish-green with hair on midrib. Leaflet margins serrated but less so than F. chiisanensis (20-30 teeth). Leaflet stalks (1)2-5(13)mm long. Flowers dioecious, sometimes mixed. Inflorescence in panicles or compound racemes in leaf axils of new branches. Calyx 4-lobed or almost entire, hairless or with fine hairs. Male flowers have stamens and 2 sepals, female flowers have 2-4 petals (oblanceolate), stamens, and pistil. Samara, 2-4cm long, wing lanceolate or elongated lanceolate, slightly pointed.

Flowering Mid-April to early June (some areas in Gangwon-do).

Fruiting September.

Distribution: Northern and northeastern China, Honshu-Kyushu in Japan; throughout Korea.

Ecological characteristics: Grows in moist, fertile soils. Somewhat light-demanding but considered intermediate between light-demanding and shade-tolerant.

Taxonomic notes: Previously, there were significant taxonomic disagreements, treating it as a synonym, subspecies, or distinct species of F. chinensis. While relatively distinct in flower sex, leaf shape, and distribution, many intermediate forms in central China suggest variety-level classification is appropriate. Some individuals in northern Gyeonggi-do and parts of Gangwon-do, with hairy winter buds and leaflet stalks, were called F. densata Nakai, but are considered individual variations of F. chinensis var. rhynchophylla. Compared to F. japonica Blume ex K. Koch in Japan, all these variations are considered continuous (Kang et al., 2002). Although F. japonica is diploid while F. chinensis var. rhynchophylla is hexaploid, their morphological similarity suggests F. japonica should be treated as a synonym of this taxon.

Japan Flora: Deciduous tKe with thick, slightly flattened branchlets; leaves 20-35 cm. long inclusive of the petioles, 5- or 7(-9)-foliolate, the leaflets narrowly broadly ovate or broadly lanceolate, 5-15 cm. long, 3-6 cm. wide, spreading white-pilose along the midrib beneath, ab­ruptly acute to short-acuminate, toothed, obliquely rounded to cuneate at base, petiolate; calyx small, cuplike, irregularly toothed, persistent; corolla absent; samaras oblanceolate, 3-4 cm. long, 5-7 mm. wide, usually obtuse, narrowly long-cune­ate at base.    Wet places in lowlands and mountains.

Hon­shu (centr. and n. distr.); often planted on borders of paddy fields. 

f. intermedia (Nakai) H.Hara. Sam­aras narrower than in the typical phase.

var. stenocarpa (Koidz.) Ohwi. Leaflets oblong to broadly oblanceolate; samaras narrowly lanceolate. Honshu (Dewa Prov.).