shiroboke flowering quince; Chaenomeles lagenaria
A specific variety of flowering quince with white blossoms. The term is primarily botanical or horticultural.
When I planted a shiroboke flowering quince in the garden, white flowers bloomed in spring.
Compound of 白 (しろ, 'white') and 木瓜 (ぼけ, 'flowering quince'). The reading ぼけ for 木瓜 is of uncertain origin.