Korea Flora: Deciduous tree. Height 30m. Winter buds and branchlets: Winter buds dark brown (black), branch tips with one terminal bud, triangular or conical, pointed, with 2 bud scales. Lateral buds opposite, smaller than terminal bud, 5-8mm × 5-10mm. Branchlets greenish-brown, hairless, flattened on one side. Leaf scars large, semi-circular. Leaves opposite, odd-pinnate compound. (7)9-11(13) leaflets, sessile, oblong-ovate or narrowly lanceolate, long acuminate, sometimes with long tail-like tips, size 7-22cm × 3-6cm. Upper surface dark green, hairless; lower surface light green with hair on veins and brown hair near the base. Sucker leaves slightly hairy on underside with winged rachis. Leaflet stalks almost absent (1-2mm). Flowers dioecious, in compound racemes from leaf axils of previous year's growth, many-flowered. No petals or sepals. Male flowers with 2 split stamens, female flowers with 2 stamens, 1 ovary, and 2-split stigma. Fruits Oblong-lanceolate samara, 2.5-4cm long, slightly notched or occasionally blunt at tip.

Sporophyte chromosome number: 48.

Flowering Mid to late April.

Fruiting September-October.

Distribution: Northeastern China, Hokkaido and northern/central Honshu in Japan; Pyongannamdo, Pyonganbukdo, Hamgyongnamdo, Hamgyongbukdo, Gangwondo to Deogyusan in Jeollabukdo, Korea.

Ecological characteristics: Grows in moist (valleys) and fertile soils, tolerates somewhat shaded areas (intermediate shade tolerance).

Taxonomic notes: Fraxinus mandshurica is difficult to distinguish from F. nigra Marsh. of central North America in terms of flowers, leaves, winter buds, and other characteristics, but is generally considered a separate species.

Japan Flora: Large deciduous tree; branches 4-angled; leaves 7- to 11-foliolate, the leaflets sessile except the terminal one, narrowly oblong, 5-15 cm. long, 3-4 cm. wide, acuminate, toothed, obliquely cuneate at base, rusty-brown woolly at the attachment, spreading-pi!osulous along mid­rib and nerves beneath, usually glabrous above; calyx minute, obconical, deciduous and not persistent in fruit; corolla absent; samaras broadly oblanceolate, obtuse, narrowly cuneate to­ward the base, 25-3.5 cm. long, 7-8 mm. wide.   Apr .-May. Wet places in mountains.

Hokkaido, Honshu (centr. and n. distr.).  occurs in Sakhalin, Korea, Manchuria, and northern e. Asia.