Mahfuzul Haque reveals how the Bangladesh National Herbarium has thrived over the past four decades
‘Dhanesh thukri’, the reddish brown and globular, native fruit is one of the rare plant types preserved at the Bangladesh National Herbarium. Scientists at the herbarium collected the fruit from Adampur forest of Kamalganj in Moulavi Bazar in 2012. Its botanical name is Hodgsonia macrocarpa of Cucurbitaceae family.
Like the Dhanesh thukri, Bangladesh National Herbarium is home to around one lakh plants including the duplicate of these. Hosne Ara, director of Bangladesh National Herbarium, says that ‘BNH dedicates its’ activities to the survey, exploration, collection, identification, and research on conservation of native plants of the country’.
Herbarium is crucial in a sense that it houses the specimens of entire flora native to the country along with information on them. The herbarium’s necessity is felt by botanists at a time when deforestation is rapidly destroying the rich flora in the country.
The Bangladesh National Herbarium, located at its own building in Mirpur in the capital, started as a development project titled ‘Botanical survey of East Pakistan’ in 1970. The project, supported by the Agricultural Research Council of Pakistan, was implemented by Dr Salar Khan and Professor Md Ismail of the botany department of University of Dhaka.
The project was renamed as ‘Botanical survey of Bangladesh’ after independence with financial support from agricultural ministry. Later, in July 1975 Bangladesh National Herbarium was established. Now it is an attached department of the environment and forest ministry.
Wild cardamom seed is another item that can be found amongst the collection of the herbarium. The cardamom seed, larger in size than the regular seed, has been collected from Lalutia of Dohazari in Chittagong in 2001. The botanical name of this rare seed is Amomum dealbatum of Zingiberaceae family.
Bangladesh is also home of Tali Palm, a monocarpic palm (botanical name: Corypha taliera), found no where else on earth except for the Dhaka university area. BNH located and identified the plant for the first time in the country and categorised it as critically endangered plant for the world. Later on, a number of persons, institutions, and NGOs took initiative to raise seedlings from its ripe fruits. Now several hundreds of those seedlings are being grown up in different places of the country for its future conservation.
The samples of other endangered plants collected at the herbarium include Bhuiya plant, Batna tree, Garsinggia, Ban Bokul, Ful Chamba, Thechu tree, and so on.
Bushra Khan, principal scientific officer of BNH, informs that a team consisting of scientists visit different spots across the country once a month, in order to collect specimens of the plants for preservation at the herbarium.
After collecting the specimens, they are preserved following a number of steps. First, the sample is kept inside the fold of a piece of newspaper.
Another two pieces of newspaper are kept on and under the paper that hold the sample. The three layers of paper then are tied with a frame called plant pressure.
The next step is to dry it in the sun. The sample is wrapped with the paper in this way so that the leaves and flowers of the specimen cannot bend.
The sample then is mounted on a sheet with the other details: the name of collector, identification number, the place from where it is collected, date, its’ usage, and so on. The samples are preserved in the special cabinets at the herbarium.
The juicy fruits are preserved in rectified spirit.
A pool of technicians looks after the collection regularly to save the collections from any kind of insects.
The sample is usually collected at the time it bears flower or fruit. ‘Because flowers or fruits are crucial for identification of the specimen later,’ Bushra Khan says.
The scientists at the herbarium preserve sample into three or four sets. One set is kept intact while the remainder of them is used to exchange with others at home or abroad with a view to do further research.
The students and researchers from home and abroad can visit the herbarium, while abiding the official procedure, for study and research. It also has a library with a vast collection of books.
The herbarium has published two books on the rare specimens of the country. It also publishes a series of floristic publication called ‘Flora of Bangladesh’. The authority of herbarium also welcomes general public who wish to visit the vast collection.
But, Bushra Khan finds inadequate number of human resource at the herbarium as a challenge. ‘If we have more officials then we will be able to conduct field visit twice a month, or more,’ she says.
Dr Md Oliur Rahman, professor of botany department at University of Dhaka, says that the herbarium is important because it showcases the entire plant generation of a country under one roof in details: the plants’ name, the place it has been found, its usage, and so on. Many plants become extinct with the course of time but the herbarium houses its existence, he says. For students and researchers, the herbarium is like a mine of information, he adds.