Fruits

I. Fruit Types Based on Morphology

A. Dry Fruits

1. Dehiscent. Ovary wall splits open and releases seeds at maturity.

Follicle. Single carpel that opens at maturity. Examples: columbine (Aquilegia), milkweed (Asclepias).

Capsule. Multiple fused carpels (compound gynoecium) that opens at maturity. Can be

septicidal. Examples: Rhododendron, Yucca, Guaiacum, Liquidambar.

loculicidal. Examples: cottonwood (Populus), crepe myrtle (Lagerstroemia), bittersweet (Celastrus).

poricidal. Example: poppy (Papaver)

circumscissile. Sometimes called a pyxis. Example: Amaranthus.

2. Indehiscent. Does not open at maturity.

Achene. One-seeded, pericarp closely fitting but not fused to seed coat. Examples: Rosa, Physocarpus, Geum, Hepatica.

Nut. From syncarpous gynoecium, with hard, thick wall. Examples: assorted nuts, beech (Fagus), oak (Quercus).

Nutlet. Basically equivalent to mericarp in families such as Lamiaceae, Hydrophyllaceae and Boraginaceae. Example: Buglossoides, Ocimum, Stachys.

Schizocarp. From syncarpous gynoecium; splits at maturity into 2 or more mericarps. Examples: maple (Acer), Geranium, Pavonia (another photo, showing 2 of the 5 mericarps intact).

Samara. An achene modifed for flight (has wings!). Example: ash (Fraxinus), elm (Ulmus).

B. Fleshy Fruits. These types have a soft and juicy pericarp (formed from the wall of the ovary). The pericarp can be further divided into the epicarp, mesocarp, and endocarp.

Berry. From multiple carpels. Examples: tomato (Solanum lycopersicum), blueberry (Vaccinium).
Drupe. From one carpel. Examples: peach (Prunus persica), plums, apricots, almonds. Note the stony endocarps.

II. Fruit Types Based on Taxonomy

A. Dry Fruits

Caryopsis. Pericarp fused to the seed coat. Fruit type found in Poaceae (the grass family). Examples: the big three, corn, wheat and rice (Zea, Triticum and Oryza), Stipa.
Legume. They come in a wide variety of morphologies, but are always from just a single carpel. Fruit type found in Fabaceae (the bean family). Examples: Pisum, peanut (Arachis), Castanospermum, Desmodium [a loment], Enterolobium, Mimosa, Pithecelobium, Rhynchosia [an Abrus mimic!].
Siliques and Silicles. Fruit type found in Brassicaceae (the cabbage family). Examples: Brassica & Thlaspi.

B. Fleshy Fruits

Hesperidium. Fruit type found in Citrus (family Rutaceae). Example: C. sinensis, C. aurantium. Close-up of rind showing oil glands.
Pepo. Example: Fruit type found in Cucurbitaceae (the gourd family). Examples: squash (Cucurbita pepo and various gourds), cross-section of cucumber.

III. Combinational and Special Fruit Types

A. Aggregate fruits (from several separate carpels, not fused). Examples:

aggregate of follicles. Example: Magnolia
aggregate of druplets. Example: raspberry (Rubus)
aggregate of achenes. Example: strawberry (Fragaria)

B. Multiple fruits. Derived from two or more flowers whose parts are often fused together at maturity. Examples:

pineapple (Ananas comosus),
fig (Ficus carica). Many tiny, wasp-pollinated flowers inside a special structure called a syconium.
sweetgum (Liquidambar). A multiple of septicidal capsules.

C. Accessory. Majority of the fleshy part of the fruit derived from structures other than the gynoecium (e.g. the receptacle). Examples:

apple (Malus). The technical term for accessory fruits in Rosaceae, Maloideae is a pome.
strawberry. (Fragaria)

Fruit illustrations from Lawrence, Figs. 40, 41, 42.

SIUC / College of Science / Elements of Plant Systematics
URL: http://www.plantbiology.siu.edu/PLB304/Fruits.html
Last updated: 22-Mar-09 / dln