Wild Flower About 300,000 wild flower plant species have so far been identified, while tens of thousands more remain undescribed. Of them only about 1,500 species (0.5%) are nurtured for food, fodder, fibre, beverage, timber, medicine and flowers. The rest are still wild. The wild plant populations occupy a central position in the earth's environment and the prime source of carbon and breathing oxygen for all living beings.
The territory of Bangladesh primarily comprises the core of Vavilov's Indo-Burma Centre of origin of cultivated plants. The study on plants in this region can be traced to a remote past in the pre-Christian era. The Charak Sanghita composed in about the 5th century BC is a valuable treatise on medicinal plants and their usages.
The systematic floristic study started in the region in the latter part of the 18th century. Some of the prominent pioneers were William roxburgh, Nathaniel Wallich and William Griffith. Sir JD Hooker's monumental work, Flora of British India was published in 7 volumes from 1872 to 1897. Bengal plants by David Prain in two volumes and Flora of Sundribuns were published in 1903. KP Biswas with a co-author published Bharatya Banawshadhi, in six volumes (1973) in Bangla. bangladesh national herbarium (BNH) was established in the early seventies and has collected a large number of plant specimens of the country. Survey, collection and preservation of the specimens are continuing.
Most of the identified (about 5,000 flowering) plants in Bangladesh are wild. About 210 species are being cultivated for food, fodder, fibre, beverage, timber, medicine, and flowers. The wild species grow silently in the vast flood plains, coastal mangrove forests, eastern hills, high plains, and large water bodies of the country. The monsoon rain, warm temperature and high humidity, floodwaters and dry winter chill are the dominant growth environment. A variable environment strongly promotes rapid evolution and may in fact be essential for speeding up evolutionary changes.
Wild flowers, both indigenous and naturalised generally grow in 5 plant communities which commonly include: 1. the flora of flood plains and crop fields; 2. the flora of roadside and homestead shrubberies; 3. the flora of forests and hills; 4. the flora of freshwater marsh; and 5. the flora of coastal strands. There is no clear-cut boundaries of these plant communities. Many species, in fact, are widely adapted and found to grow in more than one of these ecological categories. A brief description of each ecological class is given below:
The flora of floodplains and crop fields This habitat of plant communities constitutes a large area of the country. A vast tract of land is inundated by the monsoon flood for about one to three months every year. There are also upland rice fields within this habitat. The monsoon rains make this land, if not flooded, fairly wet from July to October. During the remaining months of the year there is enough soil moisture for the growth of wild species, particularly the members of Gramineae, Cyperaceae, Amaranthaceae, Araceae, Compositae, Labiatae, Polygonaceae and Scrophulariaceae. Some common flowers of this habitat are Banganda (Spilanthes iabadicensis), Bakkan, (Lippia geminata), Kulekada (Hygrophila auriculata), Choto moragphul (Gomphrena celosioides), Dholpata (Commelina benghalensis), Jhurjhuri (Serratula pallida), Kash (Thatch grass, Saccharum spontaneum), Shialkanta (Prickly popy, Argemone mexicana), etc.
The flora of roadside and homestead shrubberies This habitat comprises the lands which are generally situated above the normal annual flood level. Most of this habitat is located right in the flood plains and upland rice area of the country. The northwest and monsoon rains make the land moist for about 5 months (May to October), while for the rest of the year it is fairly dry. It is not surprising to see that many plant species are found here that are not seen in the flooded lands located only even 200 metres away. Another striking feature is the diversity in the wild species, particularly in shrubs, climbers and undergrowth herbs. Despite considerable human disturbance, a variety of wild plants grow in great numbers in this habitat. Some of the roadside and homestead flowers are Basak (Malabar nut, Adhatoda vasica), Sarpagandha (Rauwolfia serpentina), Akand (Calotropis gigantea), Bichuti (Tragia involucrata), Gobura (Anisomeles indica), Chakunda (Cassia tora), Babla (Gum tree, Acacia nilotica), Janggli shan (Crotalaria mucronata), Pitraj (Aphanamixis polystachya), Deuya (Monkey jack, Artocarpus lacucha), Kadam (Anthocephalus chinensis) and Bet (Calamus viminalis).
Flora of forests and hills The habitat encompasses the open, mixed and protected forests, and the regions of the Chittagong Hill Tracts and tea growing highlands of greater Sylhet. The major plant communities observed here are tall trees, climbers, tall grasses and herbaceous plants. Many of these species are fairly protected from direct human interferences because of their non-commercial value and inaccessibility to their growth areas. Some of them are Nal lata (Thunbergia gradiflora), Neemada (Buddleia asiatica), Gaichha lata (Calycopteris floribunda), Sada kalmi (Merrmia umbellata), Ban naranga (Gelonium multiflorum), Pahadi kash (Saccharum arundinaceum), Letkanta (Caesalpinia crista), Derish korai (Derris robusta), Bankala (Musa ornata) and many species of Orchidaceae and Zingiberaceae. The flowers of forests and hills are Ban naranga (Gelonium multiflorum), Uang-gnoen-gai (Aeschynanthus micrantha), Kukura (Leea alata), Dholsamudra (Leea macrophylla), Haldaphul (Crotolaria anagyroids), Indian Rhododendron/Straits Rhododendron (Melastoma malabathricum), Ramanigi-kela (Musa ornata), Kharkhara jam (Syzygium wallichii), Ghasphul (Arundina graminifolia), Nagabali (Mussaenda glabrata), Bandarhulla (Duabanga grandiflora), Makrishal (Schima wallichii), Shathi (Indian arrowroot, Curcuma zeoderia), and Banada (Zingiber spectabile).
Flora of freshwater marsh The country is endowed with vast and widely scattered fresh water bodies. These marshes are the low-lying wetlands where aquatic and water-loving vegetation thrive. These lands have permanent water bodies created by rain and river waters. They include reed marshes, big swamps (beel), ditches, ponds, and canals. These habitats of marshy plants are recently disturbed by irrigation projects, and through the introduction of new activities like fish and duck cultures. Many aquatic species, including the national flower (water lily), are facing extinction from their natural habitat. Most common species are Chotokut (Sagittaria sagittifolia), Hijal (India oak, Barringtonia acutangula), Helancha (Enhydra flactuans), Chandmala (Nymphoides indicum), Shapla (Water lily, Nymphaea pubescens), Patibet (Clinogyne dichotoneus), Pani kapar (Limnophila sessiliflora) and a few species of water hyacinth and other floating aquatic plants. Freshwater flowers consist of Jal kalmi (Water bindweed, Ipomoea aquatica), Chandmala (Nymphoides indicum), Shola (Indian cork-plant, Aeschynomene indica), Shhapla (Blue water lily, Nymphaea nouchali), Bilati Shhapla (Red water lily, Nymphaea nouchali), Kachuripana (Water hyacinth, Eichhornia crassipes), Badanukha (Monochoria hastata) and Jaldhaniya (Indian buttercup, Ranunculus sceleratus).
Flora of coastal strand This habitat includes coastal shorelines, tidal flats and the Sundarbans mangrove forest. The coastal strand extends along the coastline in the southern region of the country. The flora of this community is composed mostly of salt-tolerant or salt dependent species. The estuarial floras are notable, they contain more indigenous species than do other regions of the country. Besides the mangrove species, two gregarious palms form conspicuous features, the stemless Nipa palm (Nipa fruticans) in the swamps and riverbanks and the elegant Phoenix paludosa in the drier localities. Shrimp culture and other commercial activities have a negative effect on the flora and fauna of coastal zone. Most common species of this region are Hadgoza (Acanthus ilicifolius), Samudur labuni (Sesuvium portulacastrum), Pindar (Crinum asiaticum), Parash (Thespesia populnca), Bhola (Hisbiscus titiaceus), Golpata (Nypa fructicans), Hetal (Phoenix paludosa), Keya (Serew pine, Pandanus odoratissimus), Sagar nishinda (Chaste tree, Vitex trifolia) and many species of mangrove plants. Some of the flowers of coastal strand are Chhagal khuri (Ipomoea pes-caprae), Sagar kalmi (Ipomoea illustris) and Ban-shan (Wild sunhemp, Crotalaria retusa). [Noazesh Ahmed]