Aggregate fruit

A raspberry fruit (shown with a raspberry beetle larva) is an aggregate fruit, an aggregate of drupelets

The fruit of an Aquilegia flower is one fruit that forms from several ovaries of one flower, and it is an aggregate of follicles. However, because the follicles are not fused to one another, it is not considered an aggregate fruit

An aggregate fruit or etaerio (/ɛˈtɪərɪoʊ/) is a fruit that develops from the merger of several ovaries that were separate in a single flower. In contrast, a simple fruit develops from one ovary. In languages other than English, the meanings of aggregate and multiple fruit are reversed, so that aggregate fruits merge several flowers. The differences in meaning are due to a reversal in the terminology by John Lindley, which has been followed by most English-language authors.

Not all flowers with multiple ovaries form aggregate fruit; the ovaries of some flowers do not become tightly joined together to make a larger fruit. Aggregate fruits may also be accessory fruits, in which parts of the flower other than the ovary become fleshy and form part of the fruit.

The individual parts of an aggregate fruit come in many forms. Common examples are:

• drupelets:
  • Raspberry
  • Dewberry and blackberry, also an accessory fruit, with a fleshy receptacle
• achenes:
  • Strawberry, also an accessory fruit, with a fleshy receptacle
  • Ranunculus
• follicles:
  • Magnolia
• samaras:
  • Liriodendron tulipifera

A sugar apple fruit forms from the pistils and receptacle of one flower

The components of other aggregate fruit are more difficult to define. For example, sugar apple (Annona spp.) fruit are made up of individual berry-like pistils fused with the receptacle.

See also

• Multiple fruit, a structure formed from the ovaries of several flowers, that can resemble an aggregate fruit
• Compound fruit, a term sometimes used when it is not clear whether a fruit is an aggregate fruit, a multiple fruit, or a simple fruit formed from a compound ovary
• Carpel, the "building blocks" of the ovary