Types of Fruits

Fruits consist of three major types, depending on whether they are formed from a single flower with fused or unfused multiple simple pistils or from multiple flowers: (1) simple fruits consist of one simple or fused pistil, in which the pistil forms the simple fruit; (2) aggregate fruits consist of many unfused pistils as part of a single flower; and (3) multiple fruits consist of many flowers on the same floral stem fusing together during growth. Fruits formed with large areas of nonpistillate parts in the flower are known as accessory fruits, a term that may be used in combination with these other terms.

FRUIT CATEGORIES AND COMMON EXAMPLES

Major and Minor Categories of Fruit Types

Common Examples

Simple fruits Fleshy fruits

Berry (multi-seeded

Typical berry (fruits

Grape, tomato,

(develop from one

fruits with rind or skin

with skinlike

gooseberry, cranberry

pistil and often

like covering)

covering)

include

Pepo (fruits with

Cucumber, pumpkin,

surrounding

inseparable rind)

squash

[accessory] ovary

Hesperidium (fruits with

Orange, grapefruit,

tissues)

separable rind)

lemon

Drupe (single seeded with

Peach, plum, cherry, olive

thin skin)

Pome (multi-seeded fruit

Apple, pear, quince

formed from floral

tube [inferior ovary])

Dry fruits

Dehiscent fruits (fruits

Legume (single pistil

Peas, beans, locust

that split at maturity)

forming two slits)

Follicle (single pistil

Milkweed, columbine,

forming a single slit)

larkspur, magnolia

Capsule (compound

Poppy, purslane, iris,

pistil opening variously)

Saint-John's-wort,

morning glory

Nondehiscent fruits

Grain (caryopsis;

Corn, wheat, oats, rye,

(fruits that do not

one-seeded with

barley

naturally split at

inseparable covering)

maturity)

Achene (one-seeded

Sunflower, lettuce,

with separable covering)

buckwheat

Samara (winged achene)

Ash, maple, elm, birch

Nut (one-seeded,

Chestnut, walnut,

hard covered fruit with

hazelnut, acorn,

large embryo)

beechnut

Aggregate fruits

Strawberry, raspberry,

(develop from one flower

blackberry

with multiple separate

pistils)

Multiple fruits

Pineapple, mulberry,

(develop from a flower

osage orange, fig

cluster, multiple flowers

of an inflorescence)

Simple fleshy fruits are divided into three major types. Berries are multi-seeded fruits covered by a thinner skin (as in tomatoes) or a thickened rind (as in cucumbers). Some berries may be further divided into subtypes, including the pepo, characteristic of the cucumber family (e.g., cucumbers, squash, and pumpkins), and the hesperidium, characteristic of the citrus family (e.g., oranges, grapefruits, and lemons). Pomes are also multi-seeded fruits, but their fleshy body consists of largely nonfloral (accessory) parts. Since their body is not just pistil tissue, pomes can be regarded as accessory simple fruits. In pomes, the outer wall develops from the floral cup or hy-panthium of the flower, as in apples, pears, and quinces. Drupes are single-seeded fruits that may contain a leathery or stonelike seed. Peaches and plums are examples of fruits with rock-hard seeds at their center, commonly classified as stone fruits.

Simple dry fruits include two types of fruits. Dehiscent dry fruits are those that normally open during the maturation process, releasing their seeds. Frequently, a line of dehiscence forms the opening in the fruit. Legumes are formed from single pistils that have two slits or lines of dehiscence on either side of the fruit. Legumes include peanuts and beans, and legumes beans and other members of the Fabaceae family

suture line of attachment

are characteristic of the bean family. Follicles are dry fruits, often with vertical slits, which have a single dehiscence line. Capsules are formed from compound pistils and open through a variety of mechanisms. In poppies, these fruits have small pores at the top of their fruits. In contrast, irises form fruits that open along the suture lines of the compound pistil, splitting into their component pistils. The position of these openings is used to establish further subtypes (not mentioned here).

Nondehiscent dry fruits are those that do not normally open to release their seeds. Four types are commonly found. Grains, or caryopses, are small, one-seeded fruits that have fruit walls that are fused to the seed and are therefore inseparable, as in corn. Achenes are single-seeded indehiscent fruits in which the seed and fruit are readily separated, as in sunflowers. Samaras are winged fruits, such as those of maple, ash, and elm, which are readily dispersed by wind. Nuts are one-seeded fruits as well, but are characterized by their hard covering and often large and meaty embryos, as in walnuts, chestnuts, and acorns.

Aggregate fruits develop from single flowers with multiple separate pistils. Common examples composed mainly of pistillate tissues include raspberry and blackberry. The fleshy region of the strawberry originates from the receptacle of the former flower. Therefore, in addition to being an aggregate fruit, it is also called an accessory fruit.

Multiple fruits consist of the fused flowers of whole inflorescences (or flowering stalks). The most common of the multiple fruits is the pineapple, although the mulberry, Osage orange (or bois d'arc), and fig are also commonly encountered multiple fruits. see also Fruits, Seedless; Grains; Reproduction, Sexual; Rosaceae; Seed Dispersal; Seeds.

Scott D. Russell

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