The "Kuro-usugo" (Vaccinium ovalifolium) belongs to Ericaceae (the Azalea family). It is a small deciduous tree that is native from Chubu district of Honshu north to Hokkaido. This tree grows in sub-alpine forest-edges and alpine scrublands, and it can reach 50-150 cm in height. The baks is grayish-black brown, though it reddish brown when young. The leaves are broad elliptic ot broad ovate, lacking petioles, entire, and arranged in alternate. The rose-pink tinged flowers bloom descending in the axils from June to July. The fruis are produced upright and ripen purplish-black.