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Fruit

The term '''fruit''' has different meanings dependent on context, and the term is not synonymous in food preparation and biology. In botany, which is the scientific study of plants, fruits are the ripened Ovary (plants)|ovaries of flowering plants. In many plant species, the fruit includes the ripened ovary and surrounding tissues. Fruits are the means by which flowering plants disseminate seeds, and the presence of seeds indicates that a structure is most likely a fruit, though not all seeds come from fruits. No single terminology really fits the enormous variety that is found among plant fruits. The term 'false fruit' (pseudocarp, accessory fruit) is sometimes applied to a fruit like the fig (a ''multiple-accessory fruit''; see below) or to a plant structure that resembles a fruit but is not derived from a flower or flowers. Some gymnosperms, such as Taxaceae|yew, have fleshy arils that resemble fruits and some junipers have ''berry-like'', fleshy cones. The term "fruit" has also been inaccurately applied to the seed-containing female conifer cone|cones of many Pinophyta|conifers.

Botanic fruit and culinary fruit

Many true fruits, in a botanical sense, are treated as vegetables in cooking and food preparation because they are not sweet. These botanical fruits include cucurbitaceae|cucurbits (e.g., Squash (plant)|squash, pumpkin, and cucumber), tomato, peas, beans, maize|corn, eggplant, and sweet bell pepper|pepper, spices, such as allspice and Chili pepper|chillies. Occasionally, though rarely, a culinary "fruit" is branded as a true fruit in the botanical sense. For example, rhubarb is often referred to as a fruit, because it is used to make sweet desserts such as pies, though only the petiole (botany)|petiole of the rhubarb plant is edible. In the culinary sense, a fruit is usually any sweet tasting plant product associated with seed(s), a vegetable is any savoury or less sweet plant product, and a nut any hard, oily, and shelled plant product.For a Supreme Court of the United States ruling on the matter, see Nix v. Hedden. Although a Nut (fruit)|nut is a type of fruit, it is also a popular term for list of edible seeds|edible seeds, such as peanuts (which are actually a legume) and pistachios. Technically, a cereal grain is a fruit termed a caryopsis. However, the fruit wall is very thin and fused to the seed coat so almost all of the edible grain is actually a seed. Therefore, cereal grains, such as maize|corn, wheat and rice are better considered edible seeds, although some references list them as fruits. Edible gymnosperm seeds are often misleadingly given fruit names, e.g. pine nuts, Ginkgo biloba|ginkgo nuts, and juniper berries. A Folk taxonomy is a vernacular name|naming system which describes how non-scientists categorize items.

Fruit development

A fruit is a ripened ovary. Inside the ovary is one or more ovules where the megagametophyte contains the megagamete or egg cell.http://www.palaeos.com/Plants/Lists/Glossary/GlossaryL.html#M The ovules are fertilized in a process that starts with pollination, which involves the movement of pollen from the stamens to the stigma of flowers. After pollination, a tube grows from the pollen through the stigma into the ovary to the ovule and sperm are transferred from the pollen to the ovule, within the ovule the sperm unites with the egg, forming a diploid zygote. Fertilization in flowering plants involving both plasmogamy, the fusing of the sperm and egg protoplasm and karyogamy, the union of the sperm and egg nucleus. When the sperm enters the nucleus of the ovule and joins with the megagamete and the endosperm mother cell, the fertilization process is completed. As the developing seeds mature, the ovary begins to ripen. The ovules develop into seeds and the ovary wall, the ''pericarp'', may become fleshy (as in berries or drupes), or form a hard outer covering (as in nuts). In some cases, the sepals, petals and/or stamens and Gynoecium|style of the flower fall off. Fruit development continues until the seeds have matured. In some multiseeded fruits, the extent to which the flesh develops is proportional to the number of fertilized ovules. The wall of the fruit, developed from the ovary wall of the flower, is called the ''pericarp''. The ''pericarp'' is often differentiated into two or three distinct layers called the ''exocarp'' (outer layer - also called epicarp), ''mesocarp'' (middle layer), and ''endocarp'' (inner layer). In some fruits, especially simple fruits derived from an Ovary (plants)#Inferior ovary|inferior ovary, other parts of the flower (such as the floral tube, including the petals, sepals, and stamens), fuse with the ovary and ripen with it. The plant hormone ethylene causes ripening. When such other floral parts are a significant part of the fruit, it is called an ''accessory fruit''. Since other parts of the flower may contribute to the structure of the fruit, it is important to study flower structure to understand how a particular fruit forms. Fruits are so diverse that it is difficult to devise a classification scheme that includes all known fruits. Many common terms for seeds and fruit are incorrectly applied, a fact that complicates understanding of the terminology. Seeds are ripened ovules; fruits are the ripened ovaries or carpels that contain the seeds. To these two basic definitions can be added the clarification that in botanical terminology, a Nut (fruit)|nut is not a type of fruit and not another term for seed, on the contrary to common terminology. There are three basic types of fruits:
- #Simple fruit|Simple fruit
- #Aggregate fruit|Aggregate fruit
- #Multiple fruit|Multiple fruit

Simple fruit

Simple fruits can be either dry or fleshy, and result from the ripening of a simple or compound ovary with only one Carpel|pistil. Dry fruits may be either dehiscent (opening to discharge seeds), or indehiscent (not opening to discharge seeds). Types of dry, simple fruits, with examples of each, are:
- achene - (buttercup, strawberry|strawberry seeds)
- Capsule (fruit)|capsule - (Brazil nut)
- caryopsis - (wheat)
- drupe|fibrous drupe - (coconut, walnut)
- Follicle (fruit)|follicle - (milkweed)
- legume - (pea, bean, peanut)
- loment
- Nut (fruit)|nut - (hazelnut, beech, oak acorn)
- samara (fruit)|samara - (elm, Ash tree|ash, maple key)
- schizocarp - (carrot)
- silique - (radish)
- silicle - (shepherd's purse)
- utricle (fruit)|utricle - (beet) Fruits in which part or all of the ''pericarp'' (fruit wall) is fleshy at maturity are ''simple fleshy fruits''. Types of fleshy, simple fruits (with examples) are:
- berry - (redcurrant, gooseberry, tomato, avocado)
- stone fruit or drupe (plum, cherry, peach, apricot, olive)
- false berry - Epigynous accessory fruits (banana, cranberry, strawberry (edible part).)
- pome - accessory fruits (apple, pear, rosehip)

Aggregate fruit

An aggregate fruit, or ''etaerio'', develops from a flower with numerous simple pistils. An example is the raspberry, whose simple fruits are termed ''drupelets'' because each is like a small drupe attached to the receptacle. In some bramble fruits (such as blackberry) the receptacle is elongated and part of the ripe fruit, making the blackberry an ''aggregate-accessory'' fruit. The strawberry is also an aggregate-accessory fruit, only one in which the seeds are contained in achenes. In all these examples, the fruit develops from a single flower with numerous pistils. Some kinds of aggregate fruits are called berries, yet in the botanical sense they are not.

Multiple fruit

A multiple fruit is one formed from a cluster of flowers (called an ''inflorescence''). Each flower produces a fruit, but these mature into a single mass. Examples are the pineapple, edible fig, mulberry, osage-orange, and breadfruit. In the photograph on the right, stages of flowering and fruit development in the noni or Indian mulberry (''Morinda citrifolia'') can be observed on a single branch. First an inflorescence of white flowers called a head is produced. After Fertilization#Fertilisation in plants|fertilization, each flower develops into a drupe, and as the drupes expand, they become ''connate'' (merge) into a ''multiple fleshy fruit'' called a ''syncarpet''. There are also many dry multiple fruits, e.g.
- Tuliptree, multiple of samaras.
- Sweet gum, multiple of capsules.
- Sycamore and teasel, multiple of achenes.
- Magnolia, multiple of follicles.

Fruit chart

To summarize common types of fruit (examples follow in the table below):
- Berry -- simple fruit and seeds created from a single ovary
    - Pepo -- Berries where the skin is hardened, like cucurbits
    - Hesperidium -- Berries with a rind, like most citrus fruit
- False berries -- Epigynous fruit made from a part of the plant other than a single ovary
- Compound fruit, which includes:
    - Aggregate fruit -- multiple fruits with seeds from different ovaries of a single flower
    - Multiple fruit -- fruits of separate flowers, packed closely together
- Other accessory fruit -- where the edible part is not generated by the ovary