A banana is an edible fruit, botanically a berry, produced by several kinds of large herbaceous flowering plants in the genus Musa. (In some countries, bananas used for cooking may be called plantains.) The fruit is variable in size, color and firmness, but is usually elongated and curved, with soft flesh rich in starch covered with a rind which may be green, yellow, red, purple, or brown when ripe. The fruits grow in clusters hanging from the top of the plant. Almost all modern edible parthenocarpic (seedless) bananas come from two wild species – Musa acuminate and Musa balbisiana. The scientific names of most cultivated bananas are Musa acuminate, Musa balbisiana, and Musa × paradisiacal for the hybrid Musa acuminate × M. balbisiana, depending on their genomic constitution. The old scientific name Musa sapientum is no longer used.
Musa species are native to tropical Indomalaya and Australia, and are likely to have been first domesticated in Papua New Guinea. They are grown in at least 107 countries, primarily for their fruit, and to a lesser extent to make fiber, banana wine and banana beer and as ornamental plants.
There is no sharp distinction between “bananas” and “plantains” except in the Americas and Europe. In these areas, “banana” usually refers to soft, sweet, dessert bananas, particularly those of the Cavendish group, compared to Musa cultivars with their firmer, starchier fruit that are called “plantains”. In other regions, such as Southeast Asia, many more kinds of banana are grown and eaten, so the simple two-fold distinction is not useful and is not made in local languages.
The term “banana” is also used as the common name for the plants which produce the fruit. This can extend to other members of the genus Musa like the scarlet banana (Musa coccinea), pink banana (Musa velutina) and the Fe’i bananas. It can also refer to members of the genus Ensete, like the snow banana (Ensete glaucoma) and the economically important false banana (Ensete ventricosum). Both genera are classified under the banana family, Musaceae.
Photo of a banana corm growing from loamy soil
When a banana plant is mature, the corm stops producing new leaves and begins to form a flower spike or inflorescence. A stem develops which grows up inside the pseudostem, carrying the immature inflorescence until eventually it emerges at the top. Each pseudostem normally produces a single inflorescence, also known as the “banana heart”. (More are sometimes produced; an exceptional plant in the Philippines produced five.) After fruiting, the pseudo stem dies, but offshoots will normally have developed from the base, so that the plant as a whole is perennial. In the plantation system of cultivation, only one of the offshoots will be allowed to develop in order to maintain spacing. The inflorescence contains many bracts (sometimes incorrectly referred to as petals) between rows of flowers. The female flowers (which can develop into fruit) appear in rows further up the stem (closer to the leaves) from the rows of male flowers. The ovary is inferior, meaning that the tiny petals and other flower parts appear at the tip of the ovary.
The banana fruits develop from the banana heart, in a large hanging cluster, made up of tiers (called “hands”), with up to 20 fruit to a tier. The hanging cluster is known as a bunch, comprising 3–20 tiers, or commercially as a “banana stem”, and can weigh 30–50 kilograms (66–110 lb). Individual banana fruits (commonly known as a banana or “finger”) average 125 grams (0.276 lb), of which approximately 75% is water and 25% dry matter.
The fruit has been described as a “leathery berry”. There is a protective outer layer (a peel or skin) with numerous long, thin strings (the phloem bundles), which run lengthwise between the skin and the edible inner portion. The inner part of the common yellow dessert variety can be split lengthwise into three sections that correspond to the inner portions of the three carpels by manually deforming the unopened fruit. In cultivated varieties, the seeds are diminished nearly to non-existence; their remnants are tiny black specks in the interior of the fruit.
Bananas are naturally slightly radioactive, more so than most other fruits, because of their potassium content and the small amounts of the isotope potassium-40 found in naturally occurring potassium. The banana equivalent dose of radiation is sometimes used in nuclear communication to compare radiation levels and exposures.
The Musa ‘Nendran’ cultivar grown widely in the Indian state of Kerala is a member of the AAB cultivar group
The genus Musa was created by Carl Linnaeus in 1753. The name may be derived from Antonius Musa, physician to the Emperor Augustus, or Linnaeus may have adapted the Arabic word for banana, mauz. Musa is in the family Musicale. The APG III system assigns Musaceae to the order Zingiberales, part of the commelinid clade of the monocotyledonous flowering plants. Some 70 species of Musa were recognized by the World Checklist of Selected Plant Families as of January 2013; several produce edible fruit, while others are cultivated as ornamentals.
The classification of cultivated bananas has long been a problematic issue for taxonomists. Linnaeus originally placed bananas into two species based only on their uses as food: Musa sapientum for dessert bananas and Musa paradisiacal for plantains. Subsequently further species names were added. However, this approach proved inadequate to address the sheer number of cultivars existing in the primary center of diversity of the genus, Southeast Asia. Many of these cultivars were given names which proved to be synonyms.
In a series of papers published in 1947 onwards, Ernest Chessman showed that Linnaeus’s Musa sapient and Musa paradisiacal were actually cultivars and descendants of two wild seed-producing species, Musa acuminate and Musa balbisiana, both first described by Luigi Aloysius Colla .He recommended the abolition of Linnaeus’s species in favor of reclassifying bananas according to three morphologically distinct groups of cultivars – those primarily exhibiting the botanical characteristics of Musa balbisiana, those primarily exhibiting the botanical characteristics of Musa acuminate, and those with characteristics that are the combination of the two. Researchers Norman Simmonds and Ken Shepherd proposed a genome-based nomenclature system in 1955. This system eliminated almost all the difficulties and inconsistencies of the earlier classification of bananas based on assigning scientific names to cultivated varieties. Despite
In 2012, a team of scientists announced they had achieved a draft sequence of the genome of Musa acuminate.
Bananas and plantains
In regions such as North America and Europe, Musa fruits offered for sale can be divided into “bananas” and “plantains”, based on their intended use as food. Thus the banana producer and distributor Chiquita produces publicity material for the American market which says that “a plantain is not a banana”. The stated differences are that plantains are starchier and less sweet; they are eaten cooked rather than raw; they have thicker skin, which may be green, yellow or black; and they can be used at any stage of ripeness. Linnaeus made the same distinction between plantains and bananas when first naming two “species” of Musa. Members of the “plantain subgroup” of banana cultivars, most important as food in West Africa and Latin America, correspond to the Chiquita description, having long pointed fruit. They are described by Ploetz et al. as “true” plantains, distinct from other cooking bananas. The cooking bananas of East Africa belong to a different group, the East African Highland bananas, so would not qualify as “true” plantains on this definition.
Cavendish bananas are the most common dessert bananas sold
An alternative approach divides bananas into dessert bananas and cooking bananas, with plantains being one of the subgroups of cooking bananas. Triploid cultivars derived solely from M. acuminate are examples of “dessert bananas”, whereas triploid cultivars derived from the hybrid between M. acuminata and M. balbinosa (in particular the plantain subgroup of the AAB Group) are “plantains”.Small farmers in Colombia grow a much wider range of cultivars than large commercial plantations. A study of these cultivars showed that they could be placed into at least three groups based on their characteristics: dessert bananas, non-plantain cooking bananas, and plantains, although there were overlaps between dessert and cooking bananas.
In Southeast Asia – the center of diversity for bananas, both wild and cultivated – the distinction between “bananas” and “plantains” does not work, according to Valmayor et al. Many bananas are used both raw and cooked. There are starchy cooking bananas which are smaller than those eaten raw. The range of colors, sizes and shapes is far wider than in those grown or sold in Africa, Europe or the Americas. Southeast Asian languages do not make the distinction between “bananas” and “plantains” that is made in English (and Spanish). Thus both Cavendish cultivars, the classic yellow dessert bananas, and Saba cultivars, used mainly for cooking, are called pisang in Malaysia and Indonesia, kluai in Thailand and chuoi in Vietnam. Fe’i bananas, grown and eaten in the islands of the Pacific, are derived from entirely different wild species than traditional bananas and plantains. Most bananas are cooked, but Karat bananas, which are short and squat with bright red skins, very different from the usual yellow dessert bananas, are eaten raw.
In summary, in commerce in Europe and the Americas (although not in small-scale cultivation), it is possible to distinguish between “bananas”, which are eaten raw, and “plantains”, which are cooked. In other regions of the world, particularly India, Southeast Asia and the islands of the Pacific, there are many more kinds of banana and the two-fold distinction is not useful and not made in local languages. Plantains are one of many kinds of cooking bananas, which are not always distinct from dessert bananas.