A fruit is the mature, ripened ovary (or group of ovaries) of a flowering plant (angiosperm), typically containing the seeds. After fertilisation, the ovary wall (pericarp) develops into the fruit wall. The pericarp has three layers: exocarp (outer skin), mesocarp (fleshy middle), and endocarp (inner layer). An ovule becomes a seed after fertilisation; a seed is the mature ovule; a cotyledon is the seed leaf within the embryo.