How are fruits classified? A botanical guide

December 31, 2025 •

3 min read

The botanical definition of a fruit—a mature, ripened ovary of a flowering plant—is far more precise than its culinary counterpart. This distinction reveals that many items commonly used as vegetables, such as tomatoes, peppers, and cucumbers, are technically fruits, while some sweet treats like rhubarb are not. The intricate system of fruit classification helps botanists understand plant reproductive biology, evolution, and seed dispersal strategies.

Quick Summary

This article explores the botanical classification of fruits, detailing the main categories of simple, aggregate, and multiple fruits based on their floral origin. It further breaks down simple fruits into fleshy and dry types, clarifying the science behind how a fruit develops and releases its seeds.

Key Points

Origin Determines Type: Fruits are classified based on whether they develop from a single ovary of one flower (simple), multiple ovaries of one flower (aggregate), or multiple flowers (multiple).
Simple Fruits Vary: The most common type, simple fruits, can be further divided into fleshy fruits, like berries and drupes, and dry fruits, like nuts and grains.
Dry Fruits Have Subtypes: Dry fruits are categorized by whether they split open (dehiscent, like peas) or remain closed (indehiscent, like sunflower seeds) when mature.
Fleshy Fruits Are Diverse: Fleshy simple fruits include well-known types such as berries (tomatoes, grapes), drupes (peaches, olives), and pomes (apples, pears).
Culinary vs. Botanical: The botanical definition of a fruit includes many foods we consider vegetables (e.g., peppers, squash), while the culinary definition is based on taste and usage.
False Fruits Exist: Some fruits, like apples and strawberries, are 'false fruits' because part of their edible flesh comes from floral parts other than the ovary.
Aggregate and Multiple Fusion: Aggregate fruits fuse ovaries from one flower (raspberries), while multiple fruits fuse ovaries from many flowers (pineapples).

Understanding the Fundamentals of Fruit Anatomy

Before diving into the classifications, it is essential to understand the basic structure of a fruit, which develops from the fertilized ovary of a flower. The ovary wall, or pericarp, matures into the fruit wall and is often differentiated into three layers: the exocarp (the outermost skin), the mesocarp (the middle layer, often fleshy), and the endocarp (the innermost layer surrounding the seeds).

The Main Categories of Fruit

Botanists classify fruits into three primary categories based on the number of ovaries and flowers involved in their development.

Simple Fruits

Simple fruits develop from a single ripened ovary of a single flower. This is the most common category and is further divided into two major types based on the nature of the pericarp at maturity: fleshy or dry.

Fleshy Simple Fruits

Berry: Characterized by a completely fleshy pericarp containing one or more seeds. Examples often surprise people, as they include tomatoes, grapes, and bananas, as well as blueberries. Specialized berries include:
- Hesperidium: A berry with a leathery rind, like citrus fruits (oranges, lemons).
- Pepo: A berry with a hard, thick rind, such as pumpkins, cucumbers, and melons.
Drupe: Also known as a 'stone fruit,' a drupe has a fleshy outer layer (mesocarp) and a hard, stony inner layer (endocarp) enclosing a single seed. Peaches, plums, and cherries are classic examples, but so are almonds and coconuts.
Pome: A fruit with a core of seeds surrounded by fleshy tissue that develops primarily from the enlarged receptacle of the flower, making it a type of false fruit. Apples and pears are the most well-known pomes.

Dry Simple Fruits

Dehiscent Fruits: These fruits naturally split open at maturity to release their seeds.
- Follicle: Splits along one side, like a milkweed pod.
- Legume: Splits along two sides, a defining characteristic of peas, beans, and peanuts.
- Capsule: Splits in various ways, often from a multi-carpeled ovary, like the poppy.
Indehiscent Fruits: These fruits do not split open at maturity; the entire fruit serves as the dispersal unit.
- Achene: A small, single-seeded fruit where the seed is attached to the pericarp at only one point, as seen in a sunflower 'seed'.
- Nut: Features a hard, woody pericarp surrounding a single seed, such as an acorn or hazelnut.
- Caryopsis (Grain): An indehiscent fruit where the pericarp is fused to the seed coat, a defining feature of grasses like wheat and corn.

Aggregate Fruits

An aggregate fruit develops from a single flower that contains multiple ovaries. As the fruit matures, the separate ovaries (called fruitlets) fuse together into a single, combined structure. Examples include raspberries and blackberries, which are aggregates of tiny drupelets. Strawberries are also aggregate fruits, though the fleshy, red part is the receptacle and the actual fruits are the tiny achenes on the surface.

Multiple Fruits

Multiple fruits are formed from the fusion of ovaries from an entire cluster of flowers, or inflorescence, into one combined mass. The pineapple, for instance, develops from numerous individual berries fusing around a central axis. Other examples include figs and mulberries, where the individual flowers and their ovaries merge to form a larger, compound fruit.

Botanical vs. Culinary Fruit

It is common for botanical and culinary definitions of fruit to differ significantly.


Feature	Botanical Definition	Culinary Definition
Basis	Develops from a mature ovary and its contents.	Based on taste, texture, and use in meals, typically sweet.
Includes	Tomatoes, peppers, cucumbers, squash, peas, corn, and nuts.	Apples, pears, peaches, bananas, and strawberries.
Excludes	Some edible plant parts not originating from the ovary, like rhubarb stalk.	Many botanical fruits used in savory dishes, which are called 'vegetables'.
True Fruit	Develops solely from the ripened ovary.	Not a common distinction; focuses on edibility.
False Fruit	Develops from the ovary plus other floral parts (like the receptacle or thalamus).	Not a common distinction; focuses on edibility.

Conclusion

While many people identify fruits by their sweetness and culinary use, the botanical classification offers a detailed and structured understanding based on developmental origin. By categorizing fruits into simple, aggregate, and multiple types, and further distinguishing between fleshy and dry varieties, botanists provide a framework for comprehending the vast diversity of the plant kingdom. This knowledge reveals that a tomato is a berry, a raspberry is an aggregate fruit, and an apple is a false fruit, highlighting the surprising complexities that underpin plant reproduction and seed dispersal.

Optional Outbound Link: Learn more about plant biology and the significance of fruit classification on the CK-12 Foundation website.

Frequently Asked Questions

Botanically, a fruit is the mature, ripened ovary of a flowering plant that encloses the seed or seeds. This definition includes many items considered vegetables in a culinary context, like tomatoes and cucumbers.

A simple fruit develops from a single ovary within one flower, whereas an aggregate fruit forms from multiple ovaries within a single flower. A peach is a simple fruit, while a raspberry is an aggregate fruit.

Yes, from a botanical standpoint, a berry is a type of simple fleshy fruit. However, many items colloquially called 'berries,' such as raspberries (aggregate fruit) and strawberries (aggregate and false fruit), are not true botanical berries.

Dry fruits are divided into dehiscent and indehiscent categories. Dehiscent fruits split open at maturity to release seeds (e.g., peas), while indehiscent fruits remain closed (e.g., nuts and grains).

A false fruit, or accessory fruit, includes tissue derived from parts of the flower other than the ovary. Apples, pears, and strawberries are examples, as their edible flesh comes largely from the receptacle.

Botanically, a tomato is a fruit, specifically a berry, because it develops from the ovary of a flower and contains seeds. Culinarily, it is used as a vegetable in savory dishes.

Multiple fruits form from the fusion of ovaries from a cluster of flowers. Examples include pineapple, fig, and mulberry.