The floral diversity of Meghalaya is well reputed for its richness and has been a centre of attraction for many botanists. The presence of a large number of primitive flowering plants has prompted Takhtajan (1969) to call it the Cradle of Flowering Plants’. Meghalaya harbours about 3,128 species of flowering plants and contributes about 18% of the total flora of the country, including 1,237 endemic species (Khan et al 1997). A wide variety of wild cultivable plants, edible fruits, leafy vegetables and orchids are found in the natural forests of Meghalaya. However due to overexploitation, deforestation and habitat destruction many endemic and threatened species are now mainly confined to the protected areas and sacred groves.
The region is a habitat for many botanical curiosities and botanical rarities. Among insectivorous plants Nepenthes khasiana Hk. f. and two species of Drosera i.e, Drosera peltata Sm. and D. burmanii Vahl. are important. Nepenthes khasiana is endemic to Meghalaya and listed in Appendix I of CITES and placed in Schedule VI of the Wildlife (Protection) Act, 1972. The Khasi and Jaintia hills are considered to be the centre of diversity for several primitive families such as Elaeocarpaceae, Elaeagnaceae, Anonaceae, Ranunculaceae, Piperraceae, Menispermaceae, Caryophyllaceae, Lauraceae, Myricaceae, Lazarbiaceae and primitive genera like Sarcandra, Corylopis, Myrica, Magnolia and Michelia.
According to Champion & Seth (1968), major forest types in the state of Meghalaya are:-
- Assam Sub-tropical Hill Savanna
- Khasi Sub-tropical Hill Forests
- Assam Sub-tropical Pine Forests
- Assam Sub-tropical Pine Savannah
Haridasan & Rao (1985-87) recognized the following major categories of vegetation in Meghalaya based on altitude, rainfall and dominant species composition:-
- Tropical Evergreen Forests
- Tropical Semi-Evergreen Forests
- Tropical Moist and Dry Deciduous Forests
- Grasslands and Savannas
- Temperate Forests
- Sub-tropical Pine Forests
Tropical Evergreen Forests:
This forest type spreads over the lower reaches of Khasi, Jaintia and Garo hills up to 1200m and usually occurs in high rainfall areas as well as near catchment areas. The dominant tree species include Castanopsis indica, C. Tribuloides, Dysoxylum sp, Elaeocarpus sp, Engelhardtia spicata, Syzygium spp., Tetrameles nudiflora etc. which are densely interwoven by lianas. The ground flora of under shrubs and herbs include Dracaena elliptica, Leea edgeworthia, Phlogacanthus sp., and other species belonging to the family Acanthaceae, Rubiaceae, Balsaminaceae and Asteraceae. The tree trunk and branches are covered with epiphytes belonging to Ferns, Orchids, Gesneriads, Piper, mosses and many others. Lianas and climbers like Rhaphidophora spp. are also abundant.
Tropical Semi Evergreen Forests:
This forest type occupy the north and north-eastern slopes of the state up to an elevation of 1200m and with an annual rainfall of 1500-2000mm. However there are deciduous elements along with evergreen types. Careya arborea, Dillenia pentagyna, Callicarpa arborea, Tetrameles spp, etc are some of the deciduous species. Other dominant species are Elaeocarpus floribundus, Dillenia indica, Symplocos paniculata, Sapindus rarak etc. The ground flora is also much seasonal with greater representation from the Zingiberaceae family.
Tropical Moist and Dry Deciduous Forest:
This is a very prominent vegetation of Meghalaya covering a large part of East and West Garo Hills, Ri-bhoi districts etc, in areas of annual rainfall less than 1500mm and high temperature. These forests are characterised by seasonal leaf shedding and profuse flowering. The dominant tree species which are valued economically are Shorea robusta, Tectona grandis, Terminalia myriocarpa, Gmelina arborea, Artocarpus chapsala, Lagerstroemia parviflora, Maorus laevigata etc. Other associated species are Schima wallichii, Toona ciliata, Albizzia lebbeck, Dillenia pentagyna, etc. The epiphytic flora in less but orchids, ferns, Asclepidaiceae members are often seen.
Bamboo forests are not natural but occur in patches sporadically in jhum fallows. The common bamboo species are Dendrocalamus hamiltonii and Melocanna bambusoides. Some other species less frequently found are Bambusa pallida, Bambusa tulda, Chimonobambusa khasiana, etc.
Grasslands and Savannahs:
Grasslands in Meghalaya are secondary in nature and are prevalent in higher altitudes and are a result of removal of pristine forests, the relics of which could be seen amidst these grasslands as sacred groves. The dominant grass genera in the grasslands are Panicum, Paspalum, Imperata, Axonopus, Neyraudia, Sporobolus, Saccharum, Chrysopogon, Oplisminus and others along with sedges.
The temperate forests occupy the higher elevations (>1000m) with very high rainfalls (2000-5000 mm) along the Southern slopes of Khasi and Jaintia Hills. The sacred groves largely fall under this category and are the relic type evolved through millions of years. The common trees are Lithocarpus fenestratus, Castanopsis kurzii, Quercus griffithii, Q. semiserrata, Schima khasiana, Myrica esculenta, Symplocos glomerata, Photinia arguta, Ficus nemoralis, Manglietia caveana, Acer spp., Exbucklandia populnea, Engelhardtia spicata, Betula alnoides, Rhododendron arboretum, etc. Shrubs include Mahonia pycnophylla, Daphne papyraceae, Polygala arillata, Camellia caduca, Rubus spp., etc. These forest are exceptionally rich in epiphytic flora comprising Ferns, Lichens, Mosses, Orchids, Zingibers, etc.
Subtropical Pine forests:
The pine forests are confined to the higher reaches (900m – 1500 m) of the Shillong plateau in Khasi and Jaintia Hills. Pinus kesiya is the principal species which form pure stands. In certain places the pines are associated with a few broad leaved species like Schima wallichii, Myrica esculenta, Erythrina arborescence, Rhus javanica, Rhododendron arboretum, Quercus spp., etc. Shrubs include Rubus, Osbeckia, Spirea and Artemesia. During rainy season there is a profuse herbaceous undergrowth of Chrysanthemum, Aster, Hypochaeris, Prunella, Plectranthus, Desmodium, Ranunculus, Anemone, Potentilla, Clinopodium, Polygonum, Elsholtzia, etc.
Thus, it could be seen that though there is not much altitudinal variations as compared to the Himalayan states but there occurs a wide variety of vegetation types. This vegetation harbours one of the world’s richest flora and biodiversity.