What do you know about plant evolution? My hazy memories from introductory college biology center on the development of animals, while plants got short shrift. For an easy and entertaining way to fill this gap, I found “When Plants Took over the Planet” an excellent solution. Illustrator Amy Grimes and text author Chris Thorogood start with very small algae, then show how these evolved into a group of plants that includes the seaweeds, such as the giant kelp (Macrocystits pyrifera) that can grow 24 inches in a single day.
These water-based plants further evolved into land dwellers, including the lycopods, the earliest vascular plants that could grow to 100 feet tall. By contrast, the only survivors today of this group are tiny. These were followed by ferns and horsetails. Of the latter, the author writes, “Some horsetails grew to a colossal 100 feet tall. Can you imagine wandering among fat pole-like trunks of giant horsetails?” Can you imagine these plants as weeds in your garden?
The book concludes with the conifers and the wide array of flowering plants. Significant groups are colorfully illustrated, often with their typical animal associates. Thorogood summarizes the reader’s journey: “We’ve trekked through fossil forests, swum across prehistoric lakes, and climbed trees. Now we arrive on today’s green planet – a place that still teems with plant life, as it has done for millions of years.”
Excerpted from Brian Thompson’s article in the Summer 2023 issue of the Arboretum Bulletin