Bamboos are a group of woody perennial evergreen plants in the true grass family Poaceae, subfamily Bambusoideae, tribe Bambuseae. Some of its members are giants, forming by far the largest members of the grass family. They come in many forms from bushlike cattle fodder to towering culms over 120 feet high. The stems are jointed, with regular nodes; each node bears one leaf, and may also have one to several side branches. They are thus, unlike most other grasses, extensively branched; in large-growing species a single stem may carry many thousands of branchlets.

A single stem of bamboo (culm) from an established root system typically reaches full height in just one year, but then persists for several years, gradually increasing the number of side branches and branchlets.

Some species of bamboo rarely flower, some of them only every 10-100 or more years. Some of these species are monocarpic, the plant dying after the seed matures. Furthermore, all the individuals of the species will flower at the same time in a large geographical region. This is thought to have evolved to reduce the effect of predators of the seed, who would be unable to depend on a predictable food supply.

Bamboos include some 76 genera and 1500 species. They are broadly divided into “sympodial” (clumping bamboos) and “monopodial” (running bamboos), this defines the growing behavior of the rizome (bamboo’s rootlike structure). Clumping bamboo species tend to spread underground slowly. Running bamboo species are highly variable in their tendency to spread; this is related to both the species and the soil and climate conditions. The reputation of bamboo as being highly invasive is often exaggerated, and situations where it has taken over large areas is often the result of years of untended or neglected plantings.

Bamboos tolerate extremes of habitats from drought to flood and grow from sea level to 12,000 feet in elevation. They occur from Northeast Asia, south throughout East Asia west to the Himalaya, and south to northern Australia. They also occur in sub-Saharan Africa, and in the Americas from the southeast of the USA south to Chile, there reaching their furthest south anywhere, at 47°S latitude.

Established bamboo will send up shoots that generally grow to their full height in a single season, making it the fastest growing woody plant. Several subtropical bamboo species can grow 30 cm (1 foot) per day, with some species having been documented as growing over 100 cm in one day. For the species most widely cultivated in gardens, 3-5 cm per day is more typical.

Bamboo forests are self-renewing after harvest and will grow to mature stands in 5-7 years vs 10-20 years for most softwoods. Bamboo generates a crop every year. Plantations are selectively harvested without destruction to the grove. Bamboo forests can provide five times more cellulose (usable fibre) per hectare than pine forests. Unlike plantation timber, no chemical sprays or fertilisers are required to keep the bamboo forest healthy and productive.

Bamboo is the fastest growing canopy for the regreening of degraded lands, and its stands release 35% more oxygen than equivalent stands of trees. Some bamboos even sequester up to 12 tons of carbon dioxide from the air per hectare.

When bamboo is harvested for wood, care is needed to select mature stems that are several years old, as first-year stems, although full size, are not fully woody and are not strong.

Bamboo's long life makes it a Chinese symbol of long life, while in India it is a symbol of friendship. Its rare blossoming has led to the flowers' being regarded as a sign of impending famine.

Several Asian cultures, including that of the Andaman Islands, believe that humanity emerged from a bamboo stem. Malaysian legends include the story of a man who dreams of a beautiful woman while sleeping under a bamboo plant; he wakes up and breaks the bamboo stem, discovering the woman inside. In the Philippines, bamboo crosses are used as a good luck charm by farmers. In Japan, a bamboo forest sometimes surrounds a Shinto shrine as part of a sacred barrier against evils. Also, bamboo is considered second in the rank in the order of "Matsu (pine wood), Take (bamboo), Ume (plum)" and this order is used when ordering a sushi course or getting a room in a traditional Ryokan inn. Hawaiian bamboo ('ohe) is a kinolau or body form of the Polynesian creator god Kane.

Bamboo has for centuries been used in Ayurvedic medicine and Chinese herbal medicine. Tabasheer, the powdered, hardened secretion from bamboo is used internally to treat asthma, coughs and can be used as an aphrodisiac. In China, ingredients from the root of the black bamboo help treat kidney disease. Roots and leaves have also been used to treat venereal disease and cancer. Sap is said to reduce fever, and ash will cure prickly heat. A village in Indonesia reports that the water form within the culm is used to treat broken bones effectively and that the tabasheer is used to promote fertility in their cows. Current research points to bamboo's potential in a number of medicinal uses.

Bamboo related industries already provide income, food, and housing to over 2.2 billion people worldwide. Thomas Edison successfully used a carbonized bamboo filament in his experiment with the first light bulb. This light bulb still burns today in the Smithsonian Museum in Washington DC. He also used a bamboo as for the reinforcement of his swimming pool. To this day, the pool has never leaked. An unrivaled utility, uses including paper, scaffolding, diesel fuel, airplane "skins", desalination filters, aphrodisiacs, musical instruments, medicine, food and was Alexander Graham Bell's first phonograph needle.