ニシキギ科ニシキギ属の落葉高木で、学名は Euonymus sieboldianus (syn. Euonymus sieboldianus var. sieboldianus)。英名は Spindle tree。
The Spindle tree (Euonymus sieboldianus) belongs to Celastraceae (the Bittersweet family). It is a tall deciduous tree that is distributed throughout Japan, as well as the southern Korean Peninsula and Sakhalin. This tree grows in hillside to montane woodland edges and can reach 3-5 m in height. The leaves are elliptic to obovate and opposite with fine toothed edges. The small yellowish green flowers come in May and June. The fruits are capsules with four ribs. The pink arils split open and come out reddish seeds when mature. It is sometimes written as "真弓" (Mayumi: true bow), which indicates that it is a type of wood useful for making bows.
In Korean, it's called "cham-pit-sal-na-mu" (참빗살나무). This is a compound word consisting of "really" (cham: 참) + "comb teeth" (pit-sal: 빗살) + "tree" (na-mu: 나무). This is because the wood is hard and was traditionally used to make comb teeth.
Photo 11th shows the "Shiro-mi-mayumi" (white-fruited spindle tree) with a white aril,
and photo 15th shows the horticultural variety "Fuiri-mayumi" (variegated spindle tree).