Close your eyes and try to imagine what plant life looked like here on Earth 300 million years ago, when the climate was hot and humid. Forget about flowers: in those days, the world was covered with mosses and enormous tree ferns. Surprisingly, some kinds of plants that flourished in the Carboniferous period have managed to survive without evolving very much.
Take Angiopteris evecta, for example, a giant fern with fronds (fern leaves) that can grow up to 9 metres long. It belongs to a family that appeared over 300 million years ago, or close to 150 million years before flowering plants came along, making it a real witness to the distant past.
Like all ferns, it doesn’t use flowers, fruit or seeds to reproduce. Instead it still relies on a spore-based means of reproduction that is considered “primitive” because it depends on water. Male reproductive cells have to move across a film of water in order to fertilize female reproductive cells.
Another example of a “living fossil” is the Ginkgo biloba, a tree protected by Buddhist monks since the 12th century. It resembles the ginkgos that grew in the days of the last dinosaurs, 70 million years ago.
Ginkgos can reach a height of more than 25 metres, and are highly resistant to pollution, insect pests and diseases, making them excellent urban trees. Another indication of their resistance is that a gingko survived the atomic bombing of Hiroshima, even though it stood less than one kilometre from the epicentre!
Fortunately, you don’t need to travel back in time to admire these ambassadors from the past. You can see a angiopteris in the Ferns Greenhouse and a ginkgo in the Arboretum the next time you visit the Jardin botanique.