(Last Updated on : 21/03/2011)
Flora of India comprises a wide variety of plant types. India has a characteristic geographic location at the junction of the three major biogeographic realms, namely, the Indo-Malayan, the Eurasian and the Afro-tropical. It has a land frontier of about 15,200 kms and a coastline of 7,516 kms and a geographical area of about 3287.263 sq. kms. It is the seventh largest country in the world and the second largest in Asia. It is considered to be one of the twelve centres of origin and diversity of several plant species in the world.
A brief glimpse into the Geography of India will provide one with a better comprehension of the prevalence of the different types of flora found here. In terms of physical geography, the mainland of India can be divided into three distinct regions- the Himalayas, the Indo-Gangetic plain
and Peninsular India. The Himalayas form a mountain chain along the extreme northern margins of India, extending east-west about 2,500 km in length, varying in width from 240 to 340 km, occupying an area of about 500.000 sq.km in India. They rise from the low-lying Indian plains to the highest peaks at Kanchenjunga in Sikkim
. The Indo-Gangetic plain comprises alluvial low lands lying parallel to the south of the Himalaya. This region is agriculturally more productive. Peninsular India (the Deccan
, Eastern Ghats, Western Ghats) lies south to the Indo-Gangetic plain, the two being separated roughly by the boundary of Tropic of Cancer. India is mainly a tropical country but due to great altitudinal variations, almost all climatic conditions from hot deserts to cold deserts exist. There are four seasons in the year: Spring (January-March), Summer (April-June), South-West monsoon and Winter season (October-December). The south-west or the summer monsoon is the main source of rainfall in the country providing eighty percent of the precipitation, though some precipitation is received in winter months too.
The flora types of India are in accordance with the kind of geographical set-up of the land. According to World Conservation Monitoring Centre (WCMC), 1,604,000 species have been described at the global level. Thus India accounts for 8 percent of the global biodiversity existing in only 2.4 percent land area of the world. According to Nayar (1989) the number of flowering plant species endemic to the present political boundaries of this country is 4900 out of a total of 15000, i.e. 33 percent. Hajra and Mudgal (1997) report 5400 endemics in 17000 angiospermous species of India, which comes to 31.76 percent. India is an important centre of agri-biodiversity having contributed 167 species to the world agriculture and homeland for 320 species of wild relatives of crops.
The rich vegetation wealth and diversity of the country is undoubtedly due to the vast variety of the climatic and altitudinal variations coupled with varied ecological habitats. There are to be found here almost rainless areas to the highest rainfall area in the world. The altitude varies from the sea level to the highest mountain ranges of the world. The habitat types vary from the humid tropical Western Ghats to the hot desert of Rajasthan
; from cold desert of Ladakh
and icy mountains of the Himalayas to the long, warm coast line stretches of Peninsular India. The extreme diversity of the habitats has resulted in such luxuriance and variety of flora and fauna that almost all types of forests, ranging from scrub forest to the tropical evergreen rain forest, coastal mangrove to the temperate and alpine flora occur in this region. Of the various forest types found in India, the Tropical moist deciduous forest forms the major percentage of forest cover in India (almost thirty-seven percent). Tropical dry deciduous forest rank second. Thus the flora in India encompasses a wide range and variety.