Cordaites

An extinct group of the coal forests

Distant relatives of conifers and ginkophytes, the cordaites comprise an ancient group that is now extinct. These trees of the swampy forests that later gave rise to coal deposits (circa 300 Ma) had long, ribbon-like leaves, up to a meter in length, with parallel veins. Their characteristic heart-shaped ovules and their male reproductive structures (stamens) were clustered together in spikes.

Coal mines have yielded huge numbers of fossils of cordaites, calamites, ferns, lepidodendrons, sigillaria, etc.