Geography and distribution
Musa itinerans is native to south-east Asia. It is distributed from north-east India to Vietnam and the adjacent islands. The countries it is found in are China, India, Laos, Myanmar, Thailand and Vietnam.
The pseudostem of this herb is composed of closely packed leaf sheaths. Individuals commonly grow to between 3 and 7 m high, but one variety can reach 12 m. Shoots grow from a creeping, elongating rhizome (underground stem) for which the species is named 'itinerans'. The pseudostems are yellow-green, turning purple with age.
The leaf blades are ovate-oblong and reach up to 3 m in length and 90 cm in width. The semi-pendulous banana inflorescence emerges from the heart in the tip of the stem, at first a large, long-oval, tapering, dark reddish bud. As it opens, the slim, nectar-rich, tubular flowers appear. They are clustered in whorled double rows along the floral stalk, each cluster covered by a thick, waxy, hood-like bract.
Using botanical terminology, the banana fruit is actually a berry. There are up to 18 banana berries per cluster, with up to 10 clusters per infructescence (fruiting head). Each banana is up to 14 cm long and contains numerous, irregularly angled, tuberculate (with small rounded projections) seeds.
Intraspecific varieties
A recent taxonomic study distinguished six intraspecific varieties in China, based on morphological characteristics: var. chinensis , var. guangdongensis , var. lechangensis , var. xishuangbannaensis , var. annamica and var. itinerans .
Threats and conservation
Populations of Musa itinerans in the wild are generally quite small. Their natural habitat in China is increasingly under threat, as forests are being cleared for commercial agriculture.
Seed collections of this species were made in 2006 and 2007 in Yunnan, China's most biodiverse province, by the Kunming Institute of Botany (KIB), Chinese Academy of Sciences, the Millennium Seed Bank (MSB)'s Chinese partner. Seeds from these collections are held at the Germplasm Bank of Wild Species at KIB and at the MSB.
At least two varieties, annamica and lechangensis , are of conservation concern. They have been preliminarily assessed as Vulnerable (VU) by the IUCN.
Uses
The fruits of Musa itinerans are an important staple for wild Asian elephants ( Elephas maximus ) and other wildlife. The close relationship with edible bananas and plantains make this species an invaluable genetic resource for the tropical fruit industry.
Newly described varieties of Musa itinerans may have breeding value and might in the future be used for the breeding of new banana crop cultivars.
The young flowers and the pseudostem form a popular dish offered in some local restaurants in Southwest China and adjacent regions.
Millennium Seed Bank: Seed storage
Kew's Millennium Seed Bank Partnership aims to save plant life world wide, focusing on plants under threat and those of most use in the future. Seeds are dried, packaged and stored at a sub-zero temperature in our seed bank vault.
Description of seeds: Musa itinerans is the 24,200th plant species saved at Kew's Millennium Seed Bank (MSB). The seeds are 3 x 5 to 7 mm, irregularly angled and tuberculate. Duplicates of a seed accession collected by the Kunming Institute of Botany in November 2007 from Yunnan Province, China, are stored at the MSB.
Number of seed collections stored in the Millennium Seed Bank: One (collected on 2 November 2007 from Yunnan, China at 392 m above sea level, from a plant that was 3 m tall).
Cultivation
This species can stand temperatures several degrees below freezing. No common banana diseases have been observed in the wild populations, so they can be assumed to be disease-resistant.
Information about this banana's growth in the wild suggests that it could be propagated using rhizome cuttings or seeds. As a pioneer in tropical rainforests it thrives when given strong light and plentiful irrigation. Some varieties have been noted to tolerate short periods of drought. Good pest-tolerance has also been noted in some varieties.
While seeds of this species are being conserved at the Millennium Seed Bank at Wakehurst, the species is not yet being grown at Kew.
The Yunnan banana at Kew
There are three specimens of Musa itinerans in the spirit collection, within the Herbarium (one of the behind-the-scenes areas of Kew). These alcohol-preserved specimens from Thailand are available for study by bona fide researchers by appointment. The Kew spirit collection can be searched online using the Herbarium Catalogue.