Carboniferous ... shown is stem of a giant horsetail -- calamites (the one growing at an odd angle). The winged insect climbing a horsetail (equisetum) is a primitive cockroach Manoblatta sp.

This time period took place ... wet and humid. Carboniferous coal was produced by bark-bearing trees that grew in vast lowland swamp forests. Vegetation included giant club mosses, tree ferns ...