The first vascular plants
Cooksonia stands a few centimetres tall with no leaves or roots — and invents plumbing.
- When
- Known to
- ± 3 million years
- Era
- Silurian, Paleozoic
Cooksonia, from around 425 million years ago, consists of slender forking stems tipped with spore capsules. Crucially it contains vascular tissue: cells reinforced with lignin that conduct water upward and hold the plant erect. That single innovation removes the height limit imposed by diffusion, and every tree, grass and flower that follows depends on it. It had neither leaves nor roots, and grew only in damp ground.