There are very few people who do not know about the existence of the National Botanical Garden or who have not visited the National Zoo in the capital's Mirpur area. But do they know that there is a world of dried plants just beside the botanical garden? It is the Bangladesh National Herbarium (BNH) – a collection of preserved plants and associated data. Let's take a tour of it.
On the right side of the botanical garden's main entrance, there is an alley that leads to the herbarium, about 300 metres away.
A two-storey building surrounded by a garden on around one acre of land houses the herbarium. Different species of Bangladeshi plants and herbs grow on the grounds.
The fresh air from the neighbouring botanical garden fails to refresh the air inside the herbarium, which is filled with the odour of chemical preservatives.
Rows of cupboards, all locked, occupy a large portion of the hall room. Folders containing dried plants and microscopes are seen on a long laboratory desk attached to the wall of the hall.
There are laboratory glass jars on several tables containing preserved plants. Each of jar contains dry carpological collections, including Karu Korola, Dhanesh Thukri, Keyafal, Pahari banana, Ol kochu, Ban Bokul, Batna and so on. A large wild cardamom seed is also on display.
Without unlocking the cupboards, you cannot get an idea of the vast range of dried plants housed inside the herbarium. The BNH contributes to preserving the country's diverse botanic history.
The officials say that the cupboards contain more than 83,000 herbarium sheets or dried specimens of around three thousand floral species.
Usually, a whole plant or a plant's part in dried form is mounted on a sheet of paper called an herbarium sheet.
Sometimes, it may also be preserved by immersion in chemicals inside a glass jar.
The specimens are refrigerated at a temperature of minus 20 degrees Celsius. They are labelled with important information, including their scientific names, the names of the places from where they were collected, the dates of collection and the collectors' names.
"Although the herbarium was opened in 1970, we have the herbarium assessment on Adhatoda vasica or Bosak, and a bunch of dried flowers and leaves of the herb collected in 1894," said Sarder Nasir Uddin, the principal scientific officer of the BNH.
Nasir said that when researchers find it difficult to identify a plant, the BNH provides with the taxonomy of the plant.
He said, "These specimens provide the basic information for a plant's identification, and for diversity assessment of indigenous plants. This herbarium serves as a crucial reference centre for taxonomic research."
The main objective of the herbarium is to preserve regular assessments on living floral species, he added.
One by one, Nasir brought out folders of herbarium sheets from the cupboards. Many folders contain more than one record. He told The Business Standard the story of one of such folder, containing three records of Pycnarrhena pleniflora, a shrub locally called as Henalora.
"Before 2009, the BNH only had a photocopy of the plant's assessment done in 1952 for the Royal Botanic Garden in Edinburgh. In 2009 and 2011, I found the plant in Lawachhara National Park and in Adampur Forest in Moulvibazar respectively. I made its herbarium sheets. The findings indicated that the plant still exists in the wild," said Nasir.
The BNH started as a development project titled 'Botanical survey of East Pakistan' in 1970.
Prof Salar Khan and Prof Md Ismail – botany teachers of Dhaka University – implemented the project supported by the Agriculture Research Council of Pakistan.
After the formation of Bangladesh, the project was renamed 'Botanical survey of Bangladesh' financed by the Ministry of Agriculture and the Ministry of Forest, Fisheries and Livestock.
In July 1975, the Ministry of Environment and Forests included it as its department.
Finally, in 2004, it became the Bangladesh National Herbarium.
The herbarium is badly understaffed. Only five scientific officers are currently doing the work that is supposed to be done by 12 officers.
Despite the shortage of manpower, specimens are still collected through regular contributions by local researchers on botany, particularly on medicinal plants.
Khandakar Kamrul Islam is one of the researchers. He has collected specimens of several plants in expeditions across Bandarban since 2017.
Some of these plants are Ichnocarpus frutescens (local name Loilata), Crotalaria acicularis (local name Mokmol) and Cotula hemisphaerica, whose local name is unknown.
He also collected some medicinal plants.
Nasir showed us the herbarium sheet of Andrographis paniculata, locally called Kalmegh, collected by Md Ahadul.
The herbarium sheet of this plant is awaiting BNH certification.
Certification by the BNH is also required in producing medicines made from plants.
There is a library on the second floor of the herbarium containing around 4,500 journals and books from different countries. It is used by students and researchers for higher research on plant taxonomy.
In the library, one can also buy or read the 'Flora of Bangladesh' and the 'Red Data Book of Vascular Plants of Bangladesh' published by the BNH.
The library collects new books according to the demand of readers and researchers every year.
It is open to all readers from 9 am to 5 pm every day except government holidays.
However, readers require the approval of BNH Director Parimal Singha to use the library.