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 (aubergines), 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 (i.e. from a simple or a compound ovary). 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 (from Latin ).
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 (the pericarp) 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 ("veins"). 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 (see also below). 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:
Avocado contains a single large seed surrounded by an imperceptible endocarp. Avocados are, however, also sometimes classified as drupes. Banana Barberry (Berberis), Oregon-grape (Berberis aquifolium) and mayapple (Podophyllum spp.) (Berberidaceae) Strawberry tree (Arbutus unedo) (not to be confused with the strawberry (Fragaria), which is an accessory fruit), bearberry (Arctostaphylos spp.), bilberry, blueberry, cranberry, lingonberry/cowberry (Vaccinium vitis-idaea), crowberry (Empetrum spp.) (family Ericaceae) Coffee berries (Rubiaceae) (also described as drupes) "fruit a berry containing two (rarely one) seeds" Gooseberry and currant (Ribes spp.; Grossulariaceae), red, black, and white types Aubergine/Eggplant, tomato, goji berries (wolfberry) and other species of the family Solanaceae Elderberry (Sambucus niger; Viburnaceae) Indian gooseberry (Phyllanthus emblica) (Phyllanthaceae) Garcinia gummi-gutta, Garcinia mangostana (mangosteen) and Garcinia indica in the family Clusiaceae Sapodilla (Manilkara zapota), Sapotaceae Grape, Vitis vinifera in the family Vitaceae Honeysuckle: the berries of some species are edible and are called honeyberries, but others are poisonous (Lonicera spp.; Caprifoliaceae) Persimmon (Ebenaceae) Pumpkin, cucumber and watermelon in the family Cucurbitaceae
Modified berries
"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 (baobab) 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 (passion fruit) and Carica (papaya) 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 (e.g., cranberries and blueberries), and members of the family Cucurbitaceae (gourds, cucumbers, melons and squash).
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 (usually) single-seeded ovary with a hard woody layer (called the endocarp) surrounding the seed. Familiar examples include the stonefruits of the genus Prunus (peaches, plums and cherries), 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 (Hippophae rhamnoides, Elaeagnaceae), 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 (the core) 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 (Annona muricata), 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: Strawberry – the non-fleshy aggregate of seed-like achenes on its exterior is actually the "fruit", derived from an aggregate of ovaries; the fleshy part develops instead from the receptacle. Mock strawberry (Duchesnea indica) – structured just like a strawberry. Sea grape (Coccoloba uvifera; Polygonaceae) – the fruit is a dry capsule surrounded by fleshy calyx.
Berry-like conifer seed cones
The female seed cones of some conifers have fleshy and merged scales, giving them a berry-like appearance. Juniper "berries" (family Cupressaceae), 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 (Taxus species) consist of a female seed cone with which develops a fleshy red aril partially enclosing the poisonous seed.
History of terminology
The Latin word or (plural ) was originally used for "any small round fruit". Andrea Caesalpinus (1519–1603) 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 or seeds. A fleshy fruit was called a . For Caesalpinus, a true or berry was a derived from a flower with a superior ovary; one derived from a flower with an inferior ovary was called a .
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 or berry, distinguished from other types of fruit such as (drupe) and (pome). A was defined as "", meaning "unvalved solid pericarp, containing otherwise naked seeds". The adjective "" here has the sense of "solid with tissue softer than the outside; stuffed". A berry or 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 and 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 (on the fruits and seeds of plants) between 1788 and 1792. In addition to Linnaeus' eight terms, he introduced seven more, including 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 (i.e. by having "parietal placentation" in modern terminology). Nicaise Auguste Desvaux in 1813 used the terms and as further subdivisions of berries. A hesperidium, called by others (berry with a cortex), had separate internal compartments ("" in the original French) 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".
Evolution and phylogenetic significance
By definition, berries have a fleshy, indehiscent pericarp, as opposed to a dry, dehiscent pericarp. Fossils show that early flowering plants had dry fruits; fleshy fruits, such as berries or drupes, appeared only towards the end of the Cretaceous Period or the beginning of the Paleogene Period, about . The increasing importance of seed dispersal by fruit-eating vertebrates, both mammals and birds, may have driven the evolution of fleshy fruits. Alternatively, the causal direction may be the other way around. Large fleshy fruits are associated with moist habitats with closed tree canopies, where wind dispersal of dry fruits is less effective. Such habitats were increasingly common in the Paleogene and the associated change in fruit type may have led to the evolution of fruit-eating in mammals and birds.