Many subdivisions have been made, but here we need only note the main division into two great groups: Lower Gondwanas, 13,000 ft.
Thick; Upper Gondwanas, ii,000ft.
The lowest Gondwanas are very constant in character, wherever they are found; the upper members of the lower division show more variation, and this divergence of character in different districts becomes more marked in the Upper Gondwana series.
The plants of the Lower Gondwanas consist chiefly of acrogens(Equisetaceae and ferns)and gymnogens (cycads and conifers), the former being the more abundant.
The same classes of plants occur in the Upper Gondwanas; but there the proportions are reversed, the conifers, and still more the cycads, being more numerous than the ferns, whilst the Equisetaceae are but sparingly found.
In many respects the flora of the highest of these three divisions (the Panchet group) is more nearly related to that of the Upper Gondwanas than it is to the other Lower Gondwana floras.
The Damuda series, the middle division of the Lower Gondwanas, is the chief source of coal in Peninsular India, yielding more of that mineral than all other formations taken together.