The terrestrial life in the Silurian and Devonian was not that diverse as it was in the seas. Most of earth’s surface was inhabited by small plants, and giant mysterious pillars.
These pillars are thought to be a prehistoric form of a Lichen (a symbiosis between a fungus and an algal symbiont). The pillars could reach to 8 meters high, and 1 meter in diameter, and towered over the smaller 2 feet long Cooksonia plants.
Fungi (?) - Prototaxites