Compound fruit is an imprecise term sometimes applied to fruits that consist of more than a single simple unit. Because the phrase is not a strict botanical category, authors often clarify the structure by using the specific terms described below.
Forms commonly called compound fruits
- An aggregate fruit, which develops from one flower that contains several distinct ovaries; the separate ovaries mature as a group of small fruitlets associated with the same flower.
- A multiple fruit, produced when many flowers in an inflorescence each form a small fruit and those fruits fuse or press together into a single larger structure during development.
- A simple fruit that originates from a compound ovary, meaning one flower has an ovary formed by the fusion of several carpels; the resulting fruit is technically simple but develops from a multi-part ovary.
As an example of what is not a compound fruit, grapes occur in clusters but each grape is a separate berry formed from a single ovary of a single flower; the berries are not fused into a single fruit.
In technical contexts, it is clearer to avoid the catch-all label and to specify whether a fruit is aggregate, multiple, or a simple fruit from a compound ovary, since each describes a different developmental origin.