DIVERSITY OF ANGIOSPERMS IN BIHAR – AN OVERVIEW

Vinay Ranjan

Central National Herbarium, Howrah

The state of Bihar is located in the eastern part of the India. It lies between 21058′–27031′ N

latitudes and 83019′–88017′ E longitudes, and covers an area of 94163 km2. It is situated

between humid West Bengal and subhumid Uttar Pradesh in the east and west, respectively.

Bihar is bounded by an international boundary of Nepal in the north and Jharkhand in the

south. The state is divided into two unequal halves by the river Ganga, which flows through the

middle from west to east.

Bihar enjoys monsoon type of climate and is characterised throughout the state by a dry and

comparatively cool season from the middle of October to the middle of February when the

mean daily temperature varies from 70 to 100C, dry and hot summer from February to usually

sometime in June or July when mean daily maximum temperature rises up to 480C, and warm

wet season (monsoon) from June or July to September. The rainfall is derived mainly due to

south-west monsoon and highest rains are recorded in July and August. The average annual

rainfall ranges from 100 to 150 cm.

The state comes under Indo-Gangetic plain biogeographic zone (Rodger & Panwar, 1988)

and characterised by flat alluvial region, which has been under continuous and intensive

cultivation. The state has about 5720 km2 of total forest cover, including 3372 km2 dense

forest and 2348 km2 open forest. The forests in the state can be broadly categorised into

tropical moist deciduous forest, tropical dry deciduous forest and grasslands (Champion &

Seth, 1968). The tropical moist deciduous forest is dominated by ‘Sal’ (Shorea robusta) that

occurs in the Himalayan foothills towards extreme north-western boundary. The tropical dry

deciduous forest covers the maximum forest areas of the state, an open type of forest that

remains leafless during the dry season. According to National Wildlife Database Cell

(http://wiienvis.nic.in/), Bihar has 1 National Park, 12 Wildlife Sanctuaries and 1 Tiger

Reserve, covering about 3% of total geographical area of the state.

The vegetation is mainly tropophilous, and rich in plant diversity. A number of botanists in the

past have botanically explored the region to document the existing plant diversity. Anderson

(1863) published an account on the flora of Bihar based on the collection of Hooker,

Edgeworth and Thomson and also of his own. Haines (1921–1924) published his monumental

work entitled ‘Botany of Bihar and Orissa’, an account of all the known indigenous plants of

the province and of the most important or most commonly cultivated exotic ones with maps and

introduction in six parts. Mooney (1941, 1950) made additions and supplement to the Haines’s

Botany of Bihar and Orissa. Later, Saxena (1976, 1978) and Varma & Jha (1992) also made

aadditions to the flora of Bihar and Orissa. Numerous publications (Paul, 1967, 1973; Mishra

& Agarwal, 1969; Jain & al., 1975; Raizada, 1978; Misra, 1980; Varma, 1981; Singh,

1985; Singh, 1986; Bhattacharya & Sarkar, 1998) either as district floras or checklists of

plants of different areas in the state have been brought out. “Flora of Bihar – Analysis” by

Singh & al. (2001) reports a total of 2963 taxa under 1151 genera and 186 families of the

angiosperms including 16 endemic taxa, confined to the political boundary of the state, and

28 taxa endemic to India. The analysis also reports occurrence of 79 rare taxa in the state.

The flora of the state also comprises about 200 well-known medicinal plant species (Das & al.,

1999).

Habitat destruction is the principal cause for the loss of biodiversity. Anthropogenic activities,

such as encroachment and conversion of forest areas into agricultural lands, and construction of

dams and roads, and overexploitation of biological resources, pose threat to the existing

biodiversity of the state. There should be strict enforcement of rules and regulations to protect

and conserve the biodiversity. The state government has to promote activities and efforts for

the maintenance of biodiversity in the state. The biodiversity rich zones in the state may be

declared as Protected Areas to conserve the existing flora and fauna. The Forest Department

should create awareness by educating the local communities about the importance of

conserving forests and environment and sustainable utilization of biological resources for the

sustenance and posterity of human beings and make them involve in conservation activities.

Photo courtesy: Vinay Ranjan

Photo courtesy: Vinay Ranjan

REFERENCES

Anderson, T. 1863. On the flora of Bihar and the mountains of Parasnath with a list of species

collected by Messrs Hooker, Edgeworth, Thomson and Anderson. J. Asiat. Soc. Bengal,

Pt. 2, Nat. Hist. 32: 187–218.

Bhattacharyya, P.K. & Sarkar, K. 1998. Flora of West Champaran district, Bihar. Botanical

Survey of India, Calcutta.

Champion, H.G. & Seth, S.K. 1968. A revised forest types of India. Govt. of India Publications,

New Delhi.

Das, M., Bhattacharya, R.P. & Mudgal, V. 1999. Bihar. Mudgal, V. & Hajra, P.K. (Eds.),

Floristic Diversity and Conservation Strategies in India. Vol. II: In the context of States

and Union Territories. pp. 663–698. Botanical Survey of India, Calcutta.

Haines, H.H. 1921–1924. The Botany of Bihar and Orissa. Adlard & Son, London.

Jain, S.K., Banerjee, D.K. & Pal, D.C. 1975. Grasses of Bihar, Orissa and West Bengal. J.

Bombay Nat. Hist. Soc. 72: 758–773.

Mishra, A. & Agarwal, R.P. 1969. Preliminary notes on plants of Darbhanga. Videha 11–24.

Misra, M.P., Pandey, B.N. & Misra, P.N. 1980. Biological spectrum of the flora of Brachmyoni

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Misra, S.K. & Jha, D. 1972. Floristic in Darbhanga. Planta 2(1): 136–143.

Mooney, H.F. 1941. Some additions to the Botany of Bihar and Orissa. Indian For. Rec. 3: 63–

119.

Mooney, H.F. 1950. Supplement to the Botany of Bihar and Orissa. Catholic Press, Ranchi.

Paul, S.R. 1967. Studies on the grasses of Bhagalpur district (Bihar). Indian Forester 93: 169–

179.

Paul, S.R. 1973. On the aquatic and marsh flora of Monghyr, Bihar. Botanique 4: 143–152.

Raizada, G. 1978. Some interesting plants from Bihar. Indian J. Forest. 1: 61–155.

Rodgers, W.A. & Panwar, H.S. 1988. Planning a Wildlife Protected Area Network in India.

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Saxena, H.O. 1976. Additions to the Flora of Bihar & Orissa. J. Bombay Nat. Hist. Soc. 73:

553–554.

Saxena, H.O. 1978. Additions to the Flora of Bihar & Orissa. II. J. Bombay Nat. Hist. Soc. 75:

941–942.

Singh, L.B. 1985. Grasses of Saharsa district, Bihar. J. Econ. Taxon. Bot. 6: 245–246.

Singh, M.P. 1986. Flora of Patna (Dicotyledones). International Books & Periodicals Supply

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Singh, N.P., Mudgal, V., Khanna, K.K., Srivastava, S.C., Sahoo, A.K., Bandapadhyay, S.,

Aziz, N., Das, M., Bhattacharya, R.P. & Hajra, P.K. 2001. Flora of Bihar – Analysis.

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Varma, S.K. 1981. Flora of Bhagalpur – Dicotyledones. Today & Tomorrow Printers &

Publishers, New Delhi.

Varma, S.K. & Jha, R.R. 1992. Additions to the flora of Bihar. J. Bombay Nat. Hist. Soc. 89:

146–149.