Birds and Bees – Fruit Development

There is nothing better than summer fruit – nuts, peaches, nectarines, apricots, cantaloupe, watermelon, honeydew, berries, and more. They provide delicious nutrition and refreshment in the heat of summer, whether you eat them as is, whirled into a smoothie, or baked in a pie or crumble. Made into jam or jelly, or dried and preserved, you can enjoy the taste of summer in the cold, dark days of winter.

Fruit is the term used for a ripened ovary, typically from fertilized flowers (called true fruits). The term is also used for fruits that develop from other specialized cells in the ovule, other than the fertilized egg (called accessory fruits). Different fruit types develop related to the nature of the flower blossom (for a terminology refresher see: Birds and Bees – Flower Parts).

Fruit types, and their development.

Copyright @2008 Pearson Education, Inc. publishing as Pearson Benjamin Cummings

• Simple fruit (first column) – develops from a single carpel or fused carpel of a single ovary. Examples: nuts, beans, peas, tomato, orange, grape, melon, peach.
• Aggregate fruit (second column) – develops from more than one carpel, but all in the same flower. The mature carpels fuse together to form a single fruit. Examples: blackberries and raspberries.
• Multiple fruit (third column) – develops from an inflorescence or a cluster of flowers, which fuse together to form a single fruit. Examples: pineapple.
• Accessory fruit (fourth column) – does not develop from the ovary, but from another flower part such as the receptacle or hypanthium. Examples: strawberry, apples, pears.

The purpose of most fruit is to produce a seed. For some species the ovary develops into the fruit wall (the pericarp), and become soft and fleshy as the seed nears maturity (stone fruits, such as peaches). For other species, the pericarp becomes hard and dry (pea pods). Dry fruits may scatter from pods (poppy), or become very hard and retain their pericarps until they rot (acorns, almonds). When the fruit matures, it may be eaten, or remain in seed form until ready to germinate.

Learn More:

• Botany for Gardeners, by Brian Capon (Timber Press 2005). See Part V Reproduction, Chapter 9, “From Flowers to Fruits: Fruit Types”.
• Pollination and Fertilization, derived from Pollination and Fertilization, by Robert Bear and David Rintoul, for Open Stax, Rice University (Creative Commons).