Korea Flora: Deciduous shrub. Height 3m. Bark whitish-gray, peeling thinly. Branchlets have hairs and resinous glands. Leaves alternate, orbicular or ovate, apex acute or obtuse, base cuneate or rounded, 2-4cm × (1.5)2-3cm, margins serrate or double serrate, upper surface with fine hairs, lower surface with resinous glands, 5-7 pairs of veins with hairs on veins, petiole 2-5mm long, with or without hairs. Flowers: male catkins pendulous, 5-6cm long, female catkins terminal on short shoots. Fruit and Seeds: fruiting catkins 1-2cm long, erect. Bracts elliptic or broadly lanceolate, with fine hairs, lateral lobes pointing upward. Nutlet ovate-orbicular, wings equal to or narrower than body.

Sporophyte chromosome number 28, 56.Flowering period: May
Fruiting period: September-October
Distribution: Northern part of Northeast China, Inner Mongolia, Far East Russia; high mountain areas of North and South Hamgyong Provinces

Taxonomic notes: While Chinese flora recognizes Betula ovalifolia Rupr. as a species, it shows only leaf morphological variations without other distinguishing characteristics to warrant species status. Russian treatments consider it a synonym. It is likely a chromosomal variant. B. apoiensis Nakai, distributed in Hokkaido, Japan, is similar to B. humilis but is known to be of hybrid origin between B. ermanii and B. ovalifolia (Nagamitsu et al., 2006). Further taxonomic studies are needed regarding B. humilis and B. ovalifolia.