Berry (botany)


In botany, a berry is a fleshy fruit produced from a single flower containing one ovary. Berries so defined include grapes, currants, and tomatoes, as well as cucumbers, eggplants, persimmons and bananas, but exclude certain fruits that meet the culinary definition of berries, such as strawberries and raspberries. The berry is the most common type of fleshy fruit in which the entire outer layer of the ovary wall ripens into a potentially edible "pericarp". Berries may be formed from one or more carpels from the same flower. The seeds are usually embedded in the fleshy interior of the ovary, but there are some non-fleshy exceptions, such as Capsicum species, with air rather than pulp around their seeds.
Many berries are edible, but others, such as the fruits of the potato and the deadly nightshade, are poisonous to humans.
A plant that bears berries is said to be bacciferous or baccate.
In everyday English, a "berry" is any small edible fruit. Berries are usually juicy, round, brightly coloured, sweet or sour, and do not have a stone or pit, although many small seeds may be present.

Botanical berries

In botanical language, a berry is a simple fruit having seeds and fleshy pulp produced from the ovary of a single flower. The ovary can be inferior or superior. It is indehiscent, i.e. it does not have a special "line of weakness" along which it splits to release the seeds when ripe. The pericarp is divided into three layers. The outer layer is called the "exocarp" or "epicarp"; the middle layer, the "mesocarp" or "sarcocarp"; the inner layer, the "endocarp". Botanists have not applied these terms consistently. Exocarp and endocarp may be restricted to more-or-less single-layered "skins", or may include tissues adjacent to them; thus on one view, the exocarp extends inwards to the layer of vascular bundles. The inconsistency in usage has been described as "a source of confusion".
The nature of the endocarp distinguishes a berry from a drupe, which has a hardened or stony endocarp. The two kinds of fruit intergrade, depending on the state of the endocarp. Some sources have attempted to quantify the difference, e.g. requiring the endocarp to be less than 2 mm thick in a berry.
Examples of botanical berries include:
"True berries", or "baccae", may also be required to have a thin outer skin, not self-supporting when removed from the berry. This distinguishes, for example, a Vaccinium or Solanum berry from an Adansonia amphisarca, which has a dry, more rigid and self-supporting skin. The fruit of citrus, such as the orange, kumquat and lemon, is a berry with a thick rind and a very juicy interior divided into segments by septa, which is given the special name "hesperidium". A special term, pepo, is also used for fruits of the gourd family, Cucurbitaceae, which have a hard outer rind but are not internally divided by septa. The fruits of Passiflora and Carica are sometimes also considered pepos.
Berries that develop from an inferior ovary are sometimes termed epigynous berries or false berries, as opposed to true berries, which develop from a superior ovary. In epigynous berries, the berry includes tissue derived from parts of the flower other than the ovary. The floral tube, formed from the basal part of the sepals, petals, and stamens, can become fleshy at maturity and is united with the ovary to form the fruit. Common fruits that are sometimes classified as epigynous berries include bananas, coffee, members of the genus Vaccinium, and members of the family Cucurbitaceae.

Berry-like fruits

Many fruits which are berries in the culinary definition are not berries in the botanic sense, but fall into one of the following categories:

Drupes

Drupes are varyingly distinguished from botanical berries. Drupes are fleshy fruits produced from a single-seeded ovary with a hard woody layer surrounding the seed. Familiar examples include the stonefruits of the genus Prunus, olives, coconut, dates, bayberry and Persea species. Some definitions make the mere presence of an internally differentiated endocarp the defining feature of a drupe; others qualify the nature of the endocarp required in a drupe, e.g. defining berries to have endocarp less than 2 mm thick. The term "drupaceous" is used to describe fruits that have the general structure and texture of a drupe, without necessarily meeting the full definition. Other drupe-like fruits with a single seed that lack the stony endocarp include sea-buckthorn, which is an achene, surrounded by a swollen hypanthium that provides the fleshy layer. Fruits of Coffea species are described as either drupes or berries.

Pomes

The pome fruits produced by plants in subtribe Pyrinae of family Rosaceae, such as apples and pears, have a structure in which tough tissue separates the seeds from the outer softer pericarp. Although pomes are not botanical berries, Amelanchier pomes become soft at maturity, resembling a blueberry, and are commonly called Juneberries, serviceberries or Saskatoon berries.

Aggregate fruits

Aggregate or compound fruits contain seeds from different ovaries of a single flower, with the individual "fruitlets" joined at maturity to form the complete fruit. Examples of aggregate fruits commonly called "berries" include members of the genus Rubus, such as blackberry and raspberry. Botanically, these are not berries. Other large aggregate fruits, such as soursop, are not usually called "berries", although some sources do use this term.

Multiple fruits

Multiple fruits are not botanical berries. Multiple fruits are the fruits of two or more multiple flowers that are merged or packed closely together. The mulberry is a berry-like example of a multiple fruit; it develops from a cluster of tiny separate flowers that become compressed as they develop into fruit.

Accessory fruits

Accessory fruits are not botanical berries. In accessory fruits, the edible part is not generated by the ovary. Berry-like examples include:
The female seed cones of some conifers have fleshy and merged scales, giving them a berry-like appearance. Juniper "berries", in particular those of Juniperus communis, are used to flavour gin. The seed cones of species in the families Podocarpaceae and Taxaceae have a bright colour when fully developed, increasing the resemblance to true berries. The "berries" of yews consist of a female seed cone with which develops a fleshy red aril partially enclosing the poisonous seed.

History of terminology

The Latin word baca or bacca was originally used for "any small round fruit". Andrea Caesalpinus classified plants into trees and herbs, further dividing them by properties of their flowers and fruit. He did not make the modern distinction between "fruits" and "seeds", calling hard structures like nuts semina or seeds. A fleshy fruit was called a pericarpium. For Caesalpinus, a true bacca or berry was a pericarpium derived from a flower with a superior ovary; one derived from a flower with an inferior ovary was called a pomum.
In 1751, Carl Linnaeus wrote Philosophia Botanica, considered to be the first textbook of descriptive systematic botany. He used eight different terms for fruits, one of which was bacca or berry, distinguished from other types of fruit such as drupa and pomum. A bacca was defined as "pericarpium farctum evalve, semina ceteroquin nuda continens", meaning "unvalved solid pericarp, containing otherwise naked seeds". The adjective "farctus" here has the sense of "solid with tissue softer than the outside; stuffed". A berry or bacca was distinguished from a drupe and a pome, both of which also had an unvalved solid pericarp; a drupe also contained a nut and a pome a capsule, rather than the berry's naked seeds. Linnaeus' use of bacca and pomum was thus significantly different from that of Caesalpinus. Botanists continue to differ on how fruit should be classified.
Joseph Gaertner published a two-volume work, De Fructibus et Seminibus Plantarum between 1788 and 1792. In addition to Linnaeus' eight terms, he introduced seven more, including pepo for the berry-like fruits of cucurbits. A pepo was distinguished by being a fleshy berry with the seeds distant from the axis, and so nearer the fruit wall. Nicaise Auguste Desvaux in 1813 used the terms hesperidium and amphisarca as further subdivisions of berries. A hesperidium, called by others bacca corticata, had separate internal compartments and a separable membraneous epicarp or skin. An amphisarca was described as woody on the outside and fleshy on the inside. "Hesperidium" remains in general use, but "amphisarca" is rarely used.
There remains no universally agreed system of classification for fruits, and there continues to be "confusion over classification of fruit types and the definitions given to fruit terms".