Banana
is the common name for herbaceous plants of the genus Musa and for the fruit
they produce. Bananas come in a variety of sizes and colors when ripe,
including yellow, purple, and red.
Almost
all modern edible parthenocarpic bananas come from the two wild species Musa
acuminata and Musa balbisiana. The scientific names of bananas are Musa
acuminata, Musa balbisiana or hybrids Musa acuminata × Musa balbisiana,
depending on their genomic constitution. The old scientific names Musa
sapientum and Musa paradisiaca are no longer used.
Banana
is also used to describe Enset and Fe'i bananas, neither of which belong to the
Musa genus. Enset bananas belong to the genus Ensete while the taxonomy of
Fe'i-type cultivars is uncertain.
In
popular culture and commerce, "banana" usually refers to soft, sweet
"dessert" bananas. By contrast, Musa cultivars with firmer, starchier
fruit are called plantains or "cooking bananas." The distinction is
purely arbitrary and the terms 'plantain' and 'banana' are sometimes
interchangeable depending on their usage.
They
are native to tropical South and Southeast Asia, and are likely to have been
first domesticated in Papua New Guinea. Today, they are cultivated throughout
the tropics. They are grown in at least 107 countries, primarily for their
fruit, and to a lesser extent to make fiber, banana wine and as ornamental
plants.
The
banana plant is the largest herbaceous flowering plant. The plants are normally
tall and fairly sturdy and are often mistaken for trees, but their main or
upright stem is actually a pseudostem that grows 6 to 7.6 metres (20 to 24.9
ft) tall, growing from a corm. Each pseudostem can produce a single bunch of
bananas. After fruiting, the pseudostem dies, but offshoots may develop from
the base of the plant. Many varieties of bananas are perennial.
Leaves
are spirally arranged and may grow 2.7 metres (8.9 ft) long and 60 cm (2.0 ft)
wide. They are easily torn by the wind, resulting in the familiar frond look.
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.) The inflorescence contains many bracts (sometimes incorrectly
called petals) between rows of flowers. The female flowers (which can develop into
fruit) appear in rows further up the stem 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 from 30–50 kilograms (66–110 lb). In common usage,
bunch applies to part of a tier containing 3-10 adjacent fruits.
Individual
banana fruits (commonly known as a banana or 'finger') average 125 grams (0.28
lb), of which approximately 75% is water and 25% dry matter. 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 splits easily
lengthwise into three sections that correspond to the inner portions of the three
carpels.
The
fruit has been described as a "leathery berry". In cultivated
varieties, the seeds are diminished nearly to non-existence; their remnants are
tiny black specks in the interior of the fruit. Bananas grow pointing up, not
hanging down.
Bananas
are naturally slightly radioactive, more so than most other fruits, because of
their high potassium content, and the small amounts of the isotope potassium-40
found in naturally occurring potassium. Proponents of nuclear power sometimes
refer to the banana equivalent dose of radiation to support their arguments.
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