An aggregate fruit develops from a single flower with more than one pistil with multicarpellary, apocarpous, superior ovaries thus consisting of a collection of simple fruits (fruitlets).
It could be seen that in this classification of fruits, individual pistils develop into tiny drupes, however when they mature they form a clustered unit on a single receptacle (thickened part of a stem).
Examples include Custard apple, Raspberry, Blackberry, and Strawberry.
