Musa (genus)

Musa is one of two or three genera in the family Musaceae; it includes bananas and plantains. Around 70 species of Musa are known, with a broad variety of uses.

Though they grow as high as trees, banana and plantain plants are not woody and their apparent "stem" is made up of the bases of the huge leaf stalks. Thus, they are technically gigantic herbs.

Musa species are used as food plants by the larvae of some Lepidoptera species, including the giant leopard moth and other Hypercompe species, including H. albescens (only recorded on Musa), H. eridanus, and H. icasia.

Systematics and taxonomy
History
The genus Musa was first named by Carl Linnaeus in 1753. The name is a Latinization of the Arabic name for the fruit, mauz (موز). Mauz meaning Musa is discussed in the 11th-century Arabic encyclopedia The Canon of Medicine, which was translated to Latin in medieval times and well known in Europe. Muz is also the Turkish, Persian, and Somali name for the fruit. Some sources assert that Musa is named for Antonius Musa, physician to the Emperor Augustus. The word "banana" came to English from Spanish and Portuguese, which in turn apparently obtained it from a West African language (possibly Wolof).

From the time of Linnaeus until the 1940s, different types of edible bananas and plantains were given Linnaean binomial names, such as Musa cavendishii, as if they were species. In fact, edible bananas have an extremely complicated origin involving hybridization, mutation, and finally selection by humans. Most edible bananas are seedless (parthenocarpic), hence sterile, so they are propagated vegetatively. The giving of species names to what are actually very complex, largely asexual, hybrids (mostly of two species of wild bananas, Musa acuminata and Musa balbisiana) led to endless confusion in banana botany. In the 1940s and 1950s, it became clear to botanists that the cultivated bananas and plantains could not usefully be assigned Linnean binomials, but were better given cultivar names.

Sections
Ernest Entwistle Cheesman carried out a major revision of the Musaceae in the 1940s. Following his approach, the genus Musa was divided into five sections: Ingentimusa, Australimusa, Callimusa, Musa, and Rhodochlamys. These were reduced to three in 2002. Previously, the 2n = 20-chromosome species were separated into the sections Australimusa and Callimusa and the 2n = 22-chromosome species were separated into the sections Musa and Rhodochlamys. Studies have shown that genetic differences between each section in the same chromosome group are smaller than those within each section. This means the traditional separation of the sections can no longer be substantiated. Wong's studies do, however, maintain the separation between the 20- and 22-chromosome species. At present, the 2n = 14 chromosome Ingentimusa section also remains distinct.

Species
The World Checklist of Selected Plant Families accepts 68 species and two primary hybrids, as of January 2013, which are listed below. The assignment to sections is based on GRIN (where this gives the species), regrouped according to Wong et al.
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