Encyclopedia
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.
There are 91 genera and about 1,000 species of bamboo. They are found in diverse climates, from cold mountains to hot
tropical regions. 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. Major areas with no native bamboos include
Europe, north
Africa, western
Asia, northern
North America, most of
Australia, and
Antarctica.
Biology
The stems, or 'culms', can range in height from a few centimetres to 40 metres, with stem diameters ranging from 1 mm to 30 cm. The stems are jointed, with regular nodes; each node bears one side bud . These buds do not necessarily develop but are present. Buds that do develop ramify quickly with very short basal internodes into a cluster of several shoots, which usually develop into branches and occasionally into adventitious
rhizomes. Branchlets form from the branches, and leaves grow off the branchlets. They are thus, unlike most other grasses, extensively branched; in large-growing species a single stem may carry many thousands of branchlets.
Although bamboo is a grass, many of the larger bamboos are very
tree-like in appearance and they are sometimes called "bamboo trees". The reason bamboos are so different from trees is they lack a vascular cambium layer and meristem cells at the top of the culm. The vascular cambium is the perpetually growing layer of a tree's trunk beneath the bark that makes it increase in diameter each year. The meristems make the tree grow taller.
A single culm of bamboo from an established rhizome system reaches full height in one growing season, but then persists for several years, gradually increasing the number of side branches and branchlets, but growing neither broader nor taller.
Some species of bamboo rarely
flower, some of them only every 28-120 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 because it reduces the effect of predators of the seed, who would be unable to depend on a predictable food supply.
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 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. A newly transplanted bamboo plant can take 1-2 years before it sends up new shoots and will have many seasons of "sizing up" before new shoots achieve the maximum potential height for that species.
Cultivation
Many bamboos are popular in cultivation as
garden plants. In cultivation, care needs to be taken of their potential for invasive behaviour. They spread mainly through their roots and/or rhizomes, which can spread widely underground and send off new culms to break through the surface. There are two patterns for the spreading of bamboo, "clumping" and "running" . 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. Some can send out runners several metres a year, while others can stay in the same general area for long periods. If neglected, they can be invasive over time and can cause problems by moving into adjacent areas. 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.
Once established as a grove, it is difficult to completely remove bamboo without digging up the entire network of underground rhizomes. If bamboo must be removed, an alternative to digging it up is to cut down the culms, and then repeatedly mow down new shoots as they arise, until the root system exhausts its energy supply and dies. If any leaves are allowed to photosynthesize the bamboo survives and will keep spreading.
There are two main ways to prevent the spread of running bamboo into adjacent areas. The first method is rhizome pruning or "edging", which involves removing any rhizomes escaping the desired bamboo area. Hooks, shovels and picks are usual tools. The rhizomes are generally very close to the surface, so, if rhizome pruning is done twice a year, it will sever most, if not all, of the new growth. Some species may be deep running . These are much harder to control and deeper cuts will need to be made. Regular maintenance will indicate major growth directions and locations. Once the rhizomes are cut they should be removed. If any bamboo shoots come up outside of the bamboo area afterwards their presence indicates the precise location of the missed rhizome. The fibrous roots that radiate from the rhizomes do not grow up to be more bamboo so they stay in the ground.
The second involves surrounding it with a physical barrier. Concrete and specially rolled HDPE plastic are usual materials. This is placed in a 60-90 cm deep ditch around the planting, and angled out at the top to direct the rhizomes to the surface. Strong rhizomes and tools can penetrate plastic barriers with relative ease, so great care must be taken. Surrounding bamboos with barriers usually creates unhealthy bamboos with potted plant stress symptoms . Lack of water, nutrition and growing space are all causes. Also, bamboo in barriers is much more difficult to remove than free-spreading bamboo.
Barriers and edging are unnecessary for clump forming bamboos. Clump forming bamboos may eventually need to have portions taken out if they get too large.
Uses
Culinary uses
The shoots of bamboo, called
zhú sun in Chinese, are edible.
They are used in Asian stir fry, and are available in supermarkets in various sliced forms.
However, the shoots of some species contain toxins that need to be leached or boiled out before they can be eaten safely.
Pickled bamboo, used as a condiment, may also be made from the
pith of the young shoots.
The sap of young stalks tapped during the rainy season may be fermented to make
ulanzi , or simply made into a soft drink.
Zhúyèqing jiu is a green-coloured
Chinese liquor that has bamboo leaves as one of its ingredients.
Other uses
Bamboo forms a very hard wood, especially when seasoned, and is light and exceptionally tough. This makes it useful for many things such as houses , fences, bridges, toilets, walking sticks, canoes, furniture,
chopsticks, food steamers, toys, construction scaffolding, hats, martial arts weaponry,
abaci and various musical instruments such as the
shakuhachi,
palendag and
jinghu. It is also widely carved for decorative artwork. Modern companies are attempting to popularize bamboo flooring made of bamboo pieces steamed, flattened, glued together, finished, and cut. However, bamboo wood is easily infested by wood-boring insects unless treated with wood preservatives or kept very dry . It has also been used as a substitute for steel reinforcing rods in
concrete construction.
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.
Culms may be cut and hollowed into vases or drinkware, tubes, or pipes for liquids.
Culms can also serve as pipes. The Bamboo Organ of
Las Pinas,
Philippines is an example.
Bamboo canes are normally round in cross-section, but square canes can be produced by forcing the new young culms to grow through a tube of square cross-section and slightly smaller than the culm's natural diameter, thereby constricting the growth to the shape of the tube. Every few days the tube is removed and replaced higher up the fast-growing culm.
The fibre of bamboo has been used to make
paper in
China since early times. A high quality hand-made paper is still produced in small quantities. Coarse bamboo paper is still used to make
spirit money in many Chinese communities.
The wood is used for
knitting needles and the fibre can be used for
yarn and
clothing. Sharpened bamboo is also traditionally used to tattoo in Japan, Hawaii and elsewhere.
A variety of bamboo was one of about two dozen plants carried by Polynesian voyagers to provide all their needs settling new islands; in the
Hawaiian Islands, among many uses, 'Ohe carried water, made irrigation troughs for
taro terraces, was used as a traditional knife for cutting the umbilical cord of a newborn, as a stamp for dyeing bark
tapa cloth, and for four
hula instruments - nose flute, rattle, stamping pipes and
Jew's harp.
Cultural aspects
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. This is said by some to be because rats feed upon the profusion of flowers, then multiply greatly and destroy a large part of the local food supply. The most recent flowering began in May, 2006 . Bamboo is said to bloom in this manner only about every 50 years . Several Asian cultures, including that of the
Andaman Islands, believe that humanity emerged from a bamboo stem. In the
Philippine creation myth, legend tells that the first man and the first woman were split open from a bamboo stem that emerged on an island created after the battle of the elemental forces. In
Malaysian legends a similar story includes 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
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 , Take ,
Ume " and this order is used when ordering a
sushi course or getting a room in a traditional
ryokan. Hawaiian bamboo is a kinolau or body form of the Polynesian creator god Kane.
In Chinese culture, the bamboo , along with the
plum blossom ,
orchids , and
chrysanthemum are all held in high esteem and are collectively referred as "the four of great nobility" , with one representing each of the
seasons. Each also symbolises a particular aspect of the junzi in
Confucian ideology. The four plants are commonly mentioned together as "méi lán zhú jú" . The
pine tree , the bamboo and the plum blossom are also admired for their perseverance under harsh conditions, and are together known as the "Three Friends in Winter" . Here the usual order in which they are mentioned is ??? .
In
Vietnam, bamboo is the symbol of straightforward, undauntedness.
Vietnam's villages always are protected by a bamboo hedges. Bamboo hedges's also the image of union. The 3-years-old national hero in legend, Thánh Gióng rooted up a bamboo tree which had grown in road side as the weapon against Ân invader, when the iron rod had been cracked. In many wars in history, bamboo spike, bamboo stick took part in the national glorious victories.
A Vietnamese tale said that, once upon a time, there was a good poor young farmer wanted to get married to landlord's daughter. But the landlord enforced a extraordinary condition that was he must offer a " 100-sections bamboo tree". B?t appeared and helped him: "You can have a 100- sections bamboo tree if you have 100 bamboo sections from many bamboo tree". B?t gave him a magic words to glue 100 bamboo sections: "Kh?c nh?p, kh?c xu?t" . This tale means good person always be help and whenever someone has a difficult circumstance, if he has any intelligent idea, he will overcome.
Vietnamese people have a proverb:"When the bamboo is old, the bamboo sprouts apprear", it means
Vietnam will have never been annihilated, because if previous generation died,
vietnam's children will be born. Vietnamese tradition will be maintained and developed eternally.
Other aspects
Soft bamboo shoots, stems, and leaves are the major food source of the
Giant Panda of
China and the
Spider monkey.
The plant marketed as "lucky bamboo" is actually an entirely unrelated species,
Dracaena sanderiana.
See also
References and external links
