Archaeopteris was a tree-like plant with fern-like leaves. It was one of the first trees. It lived during Late Devonian and Early Carboniferous periods (385–318 million years ago). It grew to 10 m high and its trunk could exceeded 1.5 m in diameter. The veining branches diverged dichotomously.
Archaeopteris is more reminiscent of modern seed-bearing trees than other spore bearing taxa; It combines characteristics of woody trees and herbaceous ferns, and belongs to a group of extinct plants sometimes called the progymnosperms, plants with gymnosperm-like wood but that produce spores rather than seeds.
Evidence indicates that Archaeopteris preferred wet soils, growing close to river systems and in flood plain woodlands. It would have formed a significant part of the canopy vegetation of early forests.