In the succeeding carboniferous period, the plant world reached the climax of its dominion. While the variety was still very much limited, its vigor and luxuriance were astounding. The Tree-ferns seem to have come down to us unchanged from that time, but other plant descendants have dwindled in size greatly. Our humble Mares’ Tails were then twenty or thirty foot trees called Calamites. The Club-Mosses were giant Lepidodendrons. Other immense plants which have no direct descendants were the Sigillarias and the Lomatophylos. With its flexible, fluted and checkered stems, saw-edged leaves, and hanging garlands of parasitic Ferns, the carboniferous forest presented a remarkable scene.
The air was still very moist, covering the entire earth with a permanent fog and a uniform temperature. It is said that certain present-day islands in the Pacific Ocean approximate these ancient conditions.
All the plants of that time were flowerless, and belonged to neither the monocotyledonous nor the dicotyledonous classes, which include the greater number of families today. Thanks to many excellent specimens found in coal mines, it is possible for scientists to classify as many as five hundred families. It is believed that coal itself was mostly formed from small plants, but often entire trunks of the tree-like forms are found in bituminous strata. Bits of bark, cones and petrified leaves have also been unearthed at different times.
In the course of evolution, the Conifer trees were the next to develop extensively. They gained a great ascendency, but were succeeded by Palms, Alders, Cypress and Elms. By the Miocene period, all the forms known in tropic Africa today had come into existence, but were restricted by no such regional limitations as they labour under now. Oaks and Palms, Birches and Bamboos, Elms and Laurels grew side by side. The Palms reached as far north as Bohemia, Switzerland and Belgium. Maples, Lindens, Planes, Spruces, Magnolias, Persimmons and Pines flourished in Greenland. The Silver Fir and the Southern Cypress advanced to within two hundred leagues of the North Pole. The California Redwoods and Sequoias are survivors of a race which flourished in this age.
Man came very late in the earth’s evolution, but he has had a profound effect upon the plant world. His most noteworthy feat has been to take comparatively weak plants like the grains and, for his own purposes, give them large areas in which to grow. Wheat, Maize, Yams and Tobacco became widely diffused as cultivated plants before the historic era. It is probable that Rice and the Legumes were first domesticated in Asia; Barley and Wheat in Egypt; and Maize, Potatoes, Yams and Manioc in America.
The origin and development of plants is a fascinating study. So authentic are the records which they have left in the eternal rocks that we have little difficulty in reconstructing their entire race history.
THE LIFE OF A DAISY IS SPENT IN BRIGHTENING OUR FIELDS AND PASTURES
CHAPTER II
LIFE OF A PLANT
“We cannot pass a blade of grass unheeded by the way,
For it whispers to our thoughts and we its silent voice obey.”