Smaller Horsetails (sometimes of a great
size, but generally of the modern type) and Club-mosses remain,
but are not a conspicuous feature in the landscape. On the other
hand, there is as yet-- apart from the Conifers--no trace of the
familiar trees and flowers and grasses of the later world. The
vast majority of the plants are of the cycad type. These-- now
confined to tropical and subtropical regions--with the surviving
ferns, the new Conifers, and certain trees of the ginkgo type,
form the characteristic Mesozoic vegetation.
A few words in the language of the modern botanist will show how
this vegetation harmonises with the story of evolution. Plants
are broadly divided into the lower kingdom of the Cryptogams
(spore-bearing) and the upper kingdom of the Phanerogams
(seed-bearing). As we saw, the Primary Era was predominantly the
age of Cryptogams; the later periods witness the rise and
supremacy of the Phanerogams. But these in turn are broadly
divided into a less advanced group, the Gymnosperms, and a more
advanced group, the Angiosperms or flowering plants. And, just as
the Primary Era is the age of Cryptogams, the Secondary is the
age of Gymnosperms, and the Tertiary (and present) is the age of
Angiosperms.
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