Medicinal Plant Biodiversity of Bangladesh: Prospects and Problems of Conservation and Utilization

Abstract

Bangladesh contains about 5,700 species of higher plants being situated in a larger part of South-Asian center of plant genetic diversity. Of which 260 species are cultivated and the rest of the species are virtually left on growing in natural vegetation in forests and in village thickets. Chittagong Hill Tracts posses the largest tropical rain forest of Bangladesh, which includes a vast amount of plant resources. Majority of the tribal communities of the country live in this area and depend on the plant resources for their food, fuel, fruit, vegetables and medicine. The use of wild plants forms part of their traditional or indigenous systems of knowledge and practice that have accumulated and developed over generations. The widely used medicinal plant species are - Neemada, Newarpati, Mondessa (Chakma), Kanphutki, Lataphutki, Pahari bichuti, Pidaghi, Pley gach, Madanmasta, Chotrapata, Gach monsatta, Mughal mani gach, Kulla etc. Also, a vast majority of forests of Bangladesh lies in Sylhet division in the Northeast Bangladesh Ecological Zone located on a series of low hills on the southern and southeastern parts of Habiganj and Moulavibazar districts. Sylhet forests alone have 790 species of flowering plants distributed in 95 families. The most significant fact is that 25 of 95 families in this region are each represented only by a single taxon. Plant species which are becoming rare in Sylhet Region are: Kumbhi (Carea arborea), Kalija (Cordia dichotoma), Pani-hijal (Salix tetrasperma), Kurta (Plaquium polyanthum), etc. Of these wild and semi-wild plant species, medicinal and aromatic plants have been used over the millennia for human welfare in the promotion of health and as drugs and fragrance materials. In Bangladesh, the importance of medicinal plants needs no mention. Even today, use of medicinal plants in primary health care systems is very important, especially in remote rural communities and poorly accessible areas. Wild collections of herbs mainly by the poor are a livelihood activity and often a major source of cash income for these groups. Ayurvedic and Unani companies (phytopharmaceuticals) use large number of medicinal plants species as traditional medicines since ancient times. Most important medicinal plants are: Terminalia arjuna (Arjune), Terminalia chebula (Hartaki), Terminalia bellerica (Bohera), Aegle marmelos (Bael), Withania somnifera (Aswagandha), Cassia angustifolia (Sonapata), Saraca asoca (Ashok), But unfortunately, the loss of habitats and overharvesting has threatened the availability of the medicinal plants that will undermine the productivity in herbal medicines and will ultimately lead to irreversible biological loss and a high socio-economic price. Considering the threats from the loss of plant species, the Botanical Garden of Bangladesh Agricultural University has strengthened collection and conservation of threatened medicinal plant species of Chittagong Hill Tracts (CHT) and Sylhet Forests. In Bandarban (CHT), out of targeted 37 species, a total of eight plant species have so far been identified and located with the help of the local tribal herbal practitioners. The species are- Fernandoa adenophylla, Cratoxylum sumstranum, Phlogacanthus curviflorus, Hedyotis scandens, Breynia retusa, Laportea crenulata and Gynura nepalensis. The rest 29 species have not yet been located in natural habitats. Repeated search are being made with the help of the local people and the herbal practitioners to detect their occurrence in natural habitat. In Sylhet forests, a total of 29 species have been collected out of targeted 45 species, and 16 other species have not yet been collected due to their disappearance from the locality. Some of the species are- Olea dioica, Alphonsea ventricosa, Atropa beladona, Canarium bengalense, Pajnelia longifolia, Cryptoronia panic ulat a, Vernonia arborea, Cinchona officinalis.