"Natsu-haze" (Vaccinium oldhamii) belongs to Ericaceae (the Azalea family). It is a small deciduous tree that is distributed all over Japan, the northern Korean Peninsula and China. This tree grows in hills or secondary forests, and can reach 1-2 m in height. The leaves are elliptic or oblong, the edges or abaxial surface are covered with rough hairs, and arranged alternately. The racemes are borne at the terminal branches, and the pale yellowish brown flowers bloom from May to June. The fruits ripen black in fall, they have sour flavor and can be used as food.