Musa is the type genus of the banana family (Musaceae), which contains 25-80 species of bananas and plantains. Both are important throughout the world for food, shelter, medicine, and even clothing. In production, bananas are the second largest fruit crop in the world, grown in warm and tropical climates across the globe. Bananas and plantains are often said to grow on trees, but actually it's a pseudostem (false stem). The fruit also develops without pollination, which means that bananas and plantains are "virgin" fruits, and are technically berries.  Their evident importance make bananas and plantains necessary plants for the global economy.
Bananas and plantains are said to grow on trees, but in reality they grow from a large herb! Banana "trees" have a pseudostem (false stem) that is really a group of leaf stalks in a cylinder. These stalks can grow to be 20-25 ft. tall, and sprout from an underground stem called a corm or rhizome ("a thick underground horizontal stem that produces roots and has shoots that develop into new plants.")   The corm eventually pushes up through the center of the pseudostem and produces a cluster of flowers called an inflorescence that later bear fruit. Each stalk only grows one inflorescence (flower cluster) before it dies. New stalks grow out of the corm.  The banana leaves are some of the largest of all the plant species, reaching up to 9 ft. long and 2 ft. wide. They can be completely green, green on top and purple-red underneath, or green with maroon-splotches. Wind tends to shred the leaves, but the veins are still able to function properly.  Each plant has about 5-15 leaves, but 10 leaves are considered the minimum for producing mature fruit.
Bananas and plantains are herbaceous perennial monocots. The perennial portion of the plant is the corm, which stores food and grows roots for the plant. It also grows two "suckers," or vegetative shoots, the older one to produce fruit, and the younger one to replace the fruiting shoot after it dies.  The flowers begin as a pointed purple bud that grows from the tip of the stalk. Inside are double rows of white, toothed, tube-like flowers. Each cluster of flowers is covered by a waxy bract ("modified leaf that arises from the stem at the point where the flower or flower cluster develops")  that is purple and red. The first 5-15 rows are female, followed by some asexual or neuter flowers. The last rows are male flowers. The female flowers gradually develop green fruits that resemble fingers. As it grows, the inflorescence bends downward under its own weight. 
The reproduction of plantains and bananas is very unique. The fruits are produce parthenocarpically, or without pollination. The male flowers are sterile, and in some varieties so are the female flowers.  The resulting fruit forms in clusters called "hands." The bananas or plantains begin as a dark green, but gradually ripen to yellow, red, or even green-and-white striped. Their size ranges from 2 1/2 to 12 in. long and 3/4 to 2 in. in diameter. The fruit's shape is cylindrical and curved like a horn. The flesh of the fruit can be ivory white, yellow, or pinkish-yellow. The texture can be tough or gummy if unripe, and then ripens, becoming soft, slippery, or mealy. The flavor varies from sweet, mild, or even apple-like.
Many wild bananas and plantains contain seeds with very little edible flesh. Cultivated and commercially grown varieties are usually seedless. The only signs of seeds are little specks of the ovules ("a small structure in a seed plant that contains the embryo sac and develops into a seed after fertilization") in the center flesh of the fruit.  Each "hand" of fruit can contain up to 20 pieces, and there are 5-20 hands in a bunch. A bunch of Giant Cavendish, a kind of banana, contains 300-400 fruits and weighs over 100 pounds!! Oddly enough, bananas and plantains are technically berries, classified as "a soft fleshy fruit that contains many seeds."  
Plantains and bananas grow best in tropical and subtropical areas. Their ideal climate has an average temperature of 80 degrees and a mean of 4 inches of monthly rainfall. The dry season can't be more than 3 months in length. Frost, droughts, or wind can kill or severely damage both banana and plantain plants. A small amount of wind alters the plant's metabolism, but stronger winds can break the pseudostem or even uproot the entire plant. Hail is another factor that can severely damage a crop. Bananas can grow and fruit in poor soil, but they flourish in soil that is deep and well-irrigated.  In northern latitudes, root rot from waterlogged soil kills the many banana and plantain plants. Gophers can also cause them to fall down due to excessive digging. 
Wherever plantains and bananas grow, they are bothered and infected by nematodes, or parasitic worms. Some, such as Meliodogyne javanica, can cause the corm to rot. Another pest, the black weevil or Cosmopolites sordidus, infects the pseudostem. Sigatoka (leaf spot) as well as Black Sigatoka (Black Leaf Streak) require many fungicides to kill them, and can cause an epidemic among the plants. Banana Wilt or Panama Disease has been a serious plague among the banana and plantain plants in Central America. Due to some of these diseases, cultivars have been developed that are resistant to some of these infections and pests. 
Plantains and bananas serve many different purposes worldwide. Their leaves are used for plates, homemade umbrellas, and thatching (roofing); the pseudostems are made into rafts and benches. The fibers obtained from the pseudostem are used for fishing line in West Africa and fabric in the Philippines. In India, some banana fiber is even made into paper. Ash of dried peels from both bananas and plantains is used for dyeing and making soap. Various parts of the banana plant are medicinal, and used to treat anything from dysentery to burns and insect bites. These plants also contain natural antibiotics and fungicides, and are used as animal feed and fertilizer.
As a food, both plantains and bananas are eaten peeled, unpeeled, sliced, whole, ripe, or unripe. Baby food is made from banana puree, and the puree is also found in ice cream, cake, milkshakes, and other foods. Flour made from dried, unripe bananas and plantains has been mixed with wheat flour, and is used to make pastries. Fried banana and green plantain chips are popular snack foods similar to potato chips. In Africa, ripe bananas are fermented to make alcoholic beverages such as beer and wine. Musa balbisiana, a type of wild banana, has edible, male inflorescence buds that are eaten in Southeast Asia as vegetables. Young plant shoots are also cooked and considered greens in India. Grounded and roasted dried green plantains have been used as a coffee substitute.  The international popularity of bananas makes them the second largest fruit crop in the world in terms of production, grown in 130 countries and producing 155 billion pounds. Plantains produce 72 billion pounds a year and occupy 12.8 million acres in 52 nations.  These astounding figures attest to their international economic importance.
- Banana California Rare Fruit Growers, Inc.
- Banana Julia F. Morton. Purdue University- Department of Horticulture and Landscape Architecture.
- Banana and Plantain University of Georgia.
- Dictionary MSN Encarta.