DIVERSITY IN THE FLORA OF BANGLADESH: A REVIEW

Moniruzzaman Khondker

Honorary ProfessorDepartment of Botany, University of Dhaka, Dhaka - 1000, Bangladesh

Bengal Province of British IndiaA history of 200 years of Plant Science

• Present Bangladesh- a tiny part of erstwhile Bengal Province of British India and Pakistan

• Floristic work – continuation of Historical past

• 200 years before, rich in dense vegetation but without record

• 1753 Binomial nomenclature by Linnaeus brought revolution

• 1760’s students of Linnaeus & other Europeans started floristic work in Indian sub-continent

• 1793 William Roxburgh began floristic work in Bengal Province

• After which local researchers joined• Role of plants in trade, commerce, medicine, etc.

made attraction for study

William Roxburgh (1751 – 1815)Scottish surgeon and botanist, worked extensively in India

Founding father of Indian Botany

3 distinctive phases of floristic work• British period 1784-1947- Naturalization of Teak, Cinchona,

Mahogoni, etc. popularized- 1814 Roxburgh’s Hortus Bengalensis &

Flora indica in 1832 were important- Wonder plant of Burma Amherstia nobilis

attracted John Gibson in 1836- He sailed from Burma & entered current

territory of Bangladesh for investigation

Amherstia nobilis Wall. (Fam.: Fabaceae) Pride of Burma

Tectona grandis L.f. (Fam. Lamiaceae)

- Francis Hamilton, Scottish Surgeon of East India Co. (1719-1820) studied Sundarban& other parts of current Bangladesh publ. Annals of Oriental Literature

- William Griffith (1811-1845) publ. Riverineplant of Bangladesh

- Joseph Dalton Hooker’s Flora of British India (1872-1897), 7 volumes

- David Prain Bengal Plants (1903) and Flora of Sundarban (1903a)

- 1939 Department of Biology, Dhaka University formed, Herbarium founded

• Post British period to Bangladesh (1947-1971)- Datta & Mitra (1953): an account of common

plants in and around Dhaka- Sinclair (1955): Flora of Cox’s Bazar (coastal city,

of Bay of Bengal)- Khan & Aurangzeb (1959): Fam.: Acanthaceae- Hossain (1964): on Compositae- Rahman (1964): on Caesalpiniaceae- Khan and Huda (1970): Euphorbia

Bangladesh, Physiography

South Asiatic Country, lat. 20º34‘ N and 26º33‘ N, long. 88º01‘ E and 92º41‘ E, Humid tropical climate

A= 147, 570 km2 , Total population: 161 mio, Population density: 1084 ind/ km2

Major climatic factors, BangladeshAir temp., annual mean, range: 17-29 ºCHumidity, average rel., range : 70.50-78.10%Rainfall, annual total : 2334.40 mmDay length, annual range : 10.03-13.60 hLight values, mid-day, range : 714-1714 µE/m2/secAnnual total surface water inflow: 1324 billion m3

Location Map

Adaptive root system of mangrove trees

Strands of Nypa fruticans, with clear marks of high and low tide inundation by the sea

Adaptive features of breathing roots or pneumatophores

Showing excellent relationships between plants and animals

Bengal tiger (Panthera tigris tigris) from Sundarban

A saltwater crocodile (Crocodylus porosus) in Sundarbans

Tiger Fern

How the forest look from a distant

Sundarban, the mangrove forests of Bangladesh• UNESCO world heritage site. Systematic management started in 1860s.

• total Area 10,000 sq. km: 6,000 sq. km belongs to Bangladesh, rest goes to West Bengal of India, • MSL 0.9-2.11 m, inundated by high and low tides of Bay of Bengal, one ofworlds largest continuous block of mangrove forests • Total 245 genera and 334 plant species were recorded in 1903Dominant Tree Heritiera fomes

- Excoecaria agallocah- Ceriops decandra- Sonneretia apetala- Xylocarpus granatum- Bruguiera gymnorhiza- Nypa fruticans

Swamp (freshwater) Forest of Ratargul (106 spp.), Sylhet, Bangladesh: A=204.54 haCommon Plants

Pongamia glabra, Barringtonia acutangula, Syzygium fruticosum, Clinogynedichotoma, Crateva nurvula, Rosa involucrata

Contribution of Bangladesh botanists from 1971 till date

• Floristic work strengthened, after liberation of Bangladesh in 1971

• Professor Salar Khan, Department of Botany, University of Dhaka

• Bangladesh Agricultural Research Council (BARC, establ. 1973) and Bangladesh National Herbarium (BNH, establ. 1975)

Professor Salar Khan, M.Sc. (Alig.), Ph.D. (Edin.),Department of Botany, University of Dhaka

Pioneer Plant Taxonomist (1950-1981)Contributed 18 new species of Angiosperms to

the Flora of Bangladesh

Published Flora of BangladeshNo. 1-53 in between 1972 and 2002 (Prof. Khan expired in 2002)

Later on his pupils continued the activity and completed Flora of Bangladesh No. 54-63 in between 2003 and 2015

Altogether 74 families of Angiosperms were covered

Besides Prof. Khan also pioneered the Publication of Timber Yielding Plants of Bangladesh (wild and cultivated) in 1986

First Red Data Book Vol. 1 publ. in 2001 followed by Vol. 2 in 2013 by BNH

Another Red Data Book was publ. in 2013 from Dept. of Bot. Univ. Chittagong

Source: Rahman (2013)

64 species of mangrove trees, shrubs, herbs were listed, 2001

PROJECT TITLED

‘Encyclopedia of Flora and Fauna of Bangladesh’by

Asiatic Society of Bangladesh 2005-2009

• Modest venture with some distinctive feature

• Compilation includes prokaryote, higher plants, animals

• Species included report from-Present day Bangladesh-Locations that were part of East Pakistan or Lower Bengal of the Indian Subcontinent now part of the territory of Bangladesh

Angiosperms of Bangladesh in Total 7 Volumes(Dicotyledons: Vol. 6-10, Monocotyledons: Vol. 11-12)

Biodiversity in Bangladesh

112Mammals7Gymnosp.

3267Angiosp.

158Herp.-reptil.196Pteridophy.

426Marine fish248Bryophyta

251FW-fish2250Algae

2925Arthropod300BGA

475Mollusk275Fungi

1923Prot.-Acan.171Bacteria

No. of spp.Gr. Name No. of spp.Gr. Name

Updated checklist of Higher Plants of Bangladesh: A Model(could be prepared for 3267 species of Angiosperms)

Critically endangered (CR) plant, endemic to Bengal, Corypha taliera (local nameTali palm) preliminarily identified by late Prof. Salar Khan in 1950 in a scrub

jungle within the Dhaka University campus

Panicle initiated ~Sept 18, 2008, plant died Jan 23, 2010 giving ~50 kg mature fruits. Seeds were sown, new plant regenerated and planted in different parts of Bangladesh

Aldrovanda vesiculosa, Malacca Jhangi, aquatic, once avail. in Chalan beel, Rajshahi now EN

Conservation status: VU

Conservation status: CR

Conservation status: EN

Conservation status: EN

Conservation status: VU

Conservation status: CR

Conclusive remarks• Bangladesh has rich history of plant sciences• Beset with Mangrove, Sal (Shorea robusta), Mixed

Evergreen and Swamp Forests• Bulk of the Flora has already been documented• Red Data Book updated in 3 volumes• A compiled species list from Red Data Books of

Bangladesh is available with me• Able to contribute Mapping Asia Plants

Thank You