quince flower
Quince is a species of tree, Cydonia oblonga (マルメロ marumero in Japanese), related to apples and pears. It is native to the Hyrcanian forest on the south shore of the Caspian Sea, in modern day Iran. Their flowers are pink to white with five petals forming a pentagon, while their fruits are pale yellow, a bit larger than an apple. Their leaves are also noticeably "hairy", but that is very unlikely to appear except in the most exacting, detailed illustrations.
Note the distinction between this flower and the flower of the Japanese quince: a bright red flower is likely to be the latter. Quince flowers also grow singly, whereas Japanese quince flowers grow in bunches.
Example
