Bamboos are the world’s largest sized perennial grasses that belong to the grass family Poaceae, which is considered the height evolved family of the plant kingdom. Most of species of grasses are small in size and herbaceous but bamboos are tall and bushy in nature. Bamboos have many interesting and unique features. Some species of bamboos belonging to the genera Bambosa and Dendrocalamus are shrubs or trees growing to a height of 100 feet and living upto 120 years.
There are around 1200 bamboo species all over the world. India possesses about 138 species in its geographical limits. Only one species of wild bamboo namely Dendrocalamus strictus or Male Bamboo occurs in Rajasthan. This species is mainly confined to the dry deciduous forests of the state where soil depth is good on hill slopes and valleys and rainfall is better, more than 600mm per annum. Big patches of Dry bamboo brakes of Dendrocalamus strictus are mainly confined in southern Rajasthan, mainly in Udaipur, Pratapgarh, Chittorgarh, the eastern part of Pali district (in Kumbhalgarh Wildlife Sanctuary) and in Mt. Abu of Sirohi district. Other districts of southern Rajasthan presently possess smaller patches of bamboo brakes.
Dendrocalamus Genus posses 25 species in the world. Dendrocalamus giganteus, the Giant Bamboo is the largest bamboo, grows with great rapidity, even as much as 46 cm a day or nearly 2cm per hour. Bamboo culm is considered the world’s fastest-growing plant tissue. Dendrocalamus strictus, which is confined to Rajasthan state has solid or nearly solid stems, was used for making lances during princely state time.
Flowering is the most fascinating phenomenon of bamboo’s life cycle. Bamboos have two types of unique flowering pattern, sporadic flowering and gregarious flowering. Most of the bamboo flowers only once in their lifetime. After flowering, they produces seeds and then die forever. Before flowering, bamboos grow vegetatively, making clumps of varying sizes. Till flowering, clump grows continuously and remains green. Different bamboo species have different flowering cycles. Some species of bamboos flower only once every 40 to 50 years.
Dendrocalamus strictus bamboo flowers in the winter season. Sporadic flowering is a regular phenomenon seen every year when only a few clumps of bamboos of a big chunk of forest area starts flowering. Now greenness of a flowering clump starts decreasing and drying also starts simultaneously. By the month of May, fruits reach the ripening stage. After ripening the fruits, fast-drying appears in all the culms of the clump and in underground rhizome also. Soon in July, monsoon sets in. Now all the trees, bush and other forms of plants start fast re-leafing, rejuvenating, branching, but flowered bamboos start dying and rotting. Within next few months, they become fully dead and dried. Now from the green color, they turned into black colour. Now, In a green landscape, they present a contrast black color.
The most impressive, notable, and interesting phenomenon is bamboos’ gregarious flowering which is actually a synchronized flowering of this specie. When such type of flowering starts, every individual clump of a chunk of forest land, starts flowering irrespective of its age. Now every bamboo plant seems in a hurry to flower and to die. When gregarious flowering starts, thousands of thousand bamboo plants of a hilly slope or valley becomes yellowish in color, all flowers at once. Spherical clusters of flowers appear on every node of branchlet towards extremities of culms and their branches. Now the forest scene becomes picturesque and unforgettable. This phenomenon of flowering starts in winter in Rajasthan and ends in May. Being monocarpic in nature, after the ripening of seeds, the whole bamboo forest dies at once and spare all the occupied space to the new generation yet to come. This is the season when the forest becomes very vulnerable to fire as the dead and dry bamboos provide the best combustible material in the forest area. This is also a bad season for humans as well because rodents’ numbers start increasing fast in the forest area. Since now enormous food is available in the forest in the form of bamboo seeds which is much liked by the rats and mice. Being a prolific breeder, these rodents take full advantage of surplus food and increase their population very fast. This swarming population of rats and mice subsequently may cause famine and loss of lives and livelihoods
Gregarious flowering happens at long intervals. Different species have different flowering cycles, anywhere between 60 to 130 years. Many adverse factors are responsible for flowering in bamboos. It has been noted that severe attack of pests or disease, injury, malnutrition, or long period of prolonged drought and floods are responsible for the flowering.
There are very few forest officers in this world who have seen gregarious bamboo flowering in their service tenure. Last gregarious bamboo flowering of Rajasthan is not of records. During the last 50 years, too gregarious bamboo flowering happened in the state on a small scale. During winters of 1995-96, gregarious flowering was seen in Mount Abu Wildlife Sanctuary when nearly 700 ha bamboo forest of Dendrocalamus strictus of Abu Forest Block 1 set in blooming. A similar bamboo flowering noted during this year (2019-20) in the Nal Mokhi forest of Gogunda tehsil of Udaipur district. One who loves to see this unique phenomenon of nature can take the opportunity to see and photograph nature’s wonder in the Nal Mokhi forest.