Note: Do not rely on this information. It is very old.
Quince (Cydonia vulgaris), a tree belonging to the sub-order Pomaceae, of the rose tribe, with leafy calyx-lobes and more than the two seeds in each division of the core, which are characteristic of Pyrus, the genus to which apple, pear, and mountain ash belong. It is a native of the Mediterranean region, flowers in May or June, and bears a large golden-yellow fruit of variable form, fragrant odour, but, when raw, of austere flavour. It is cooked with apples, and was the original ingredient of marmalade, marmelo being the Portuguese name of the fruit. The quince is used as a stock on which to graft pears.