Botany
Small- to medium-sized deciduous tree growing to a height of 15 m. Leaves are alternate, narrow-elliptic, acuminate, wedge-shaped at the base, up to 12 cm long, glossy and dark green above and pale underneath, the margins slightly toothed. Flowers are staminate, in long catkins; the pistillate flowers are in short catkins, becoming woody cones with 5-lobed scales.

Distribution
Indigenous to Korea.
Grows in Baguio and other parts of the Mountain Province.
Propagated by seed or grafting.

Constituents and properties
(1) Hepatoprotective and antioxidant effects of Alnus japonica extracts on acetaminophen-induced hepatotoxicity in rats.
(2) Two diarylheptanoids, oregonin and hirsutanone were isolated by bioassay-guided fractionation of the methanol extracts of the leaves of Alnus japonica Steud and their structures were elucidated from their spectroscopic data. Compounds exhibited significant low-density lipoprotein (LDL)-antioxidant activities. (http://www.cababstractsplus.org/google/abstract.asp?AcNo=20053088158)

Parts used
Stem bark, leaves.

Uses
As used in South East Asian countries
Popular folk medicine in Korea for cancer and hepatitis.
Various species of alder, including this species, seem to contain antitumour compounds.
Other uses
Dye is obtained fromm the bark.
Wood - close grained; used for turnery, charcoal.
Studies
(1) Hepatoprotective and antioxidant effects of Alnus japonica extracts on acetaminophen-induced hepatotoxicity in rats.
(2) investigation of the phenolic components of the wood of Alnus japonica Steud.
(3) Antioxidant effects of diarylheptanoid derivatives from Alnus japonica on human LDL oxidation: Planta Medica, 2005 (Vol. 71) (No. 4) 295-299