バラ科ナナカマド属の落葉中高木で、学名は Sorbus alnifolia (syn. Micromeles alnifolia)。英名は Korean mountain ash。
The Korean mountain ash (Sorbus alnifolia) belongs to Rosaceae (the Rose family). It is a semi-tall deciduous tree that is native to Japan, as well as Taiwan, the Korean Peninsula and China. This tree grows in montane ridges and can reach about 10 m in height. The barks are black-brown and smooth. The leaves are ovate to elliptic and alternate with shallow duplicato-serratus edges. The compoundcorymbs are borne on the terminal branches and the white flowers bloom from April to June. The fruit is a pome-like fruit and is used to make a fruit wine. The Japanese name "Azuki-nashi" comes from the red "adzuki-bean" like fruit it bears in the fall. In Taiwanese Chinese, it is called "赤楊葉梨" and in Chinese, "水楡花楸" (shui yu hua qiu).
In Korean, it's called "pat-bae-na-mu" (팥배나무). This is a compound word consisting of "Azuki bean" (pat: 팥) + "pear" (bae: 배) + "tree" (na-mu: 나무). Just like its Japanese name suggests, the tree bears small fruits resembling azuki beans, and it is named for the pear-like spots on their surface.