Sigillaria is an extinct genus of tree-sized lycopods from the Carboniferous Period (360 to 300 million years ago) that are related to the modern club mosses. The columnar trunks rarely branched and were characterized by leaf scars arranged in vertical aligned rows. Both the leaves and the roots are indistinguishable from those of Lepidodendron. The cones were borne on short stalks which were attached to whorls at certain zones in the stem. Sigillaria appears to have preferred mineral soils of river floodplains in contrast to the Lepidodendrons which grew in the peat-forming mires. This preference for more well-drained soils may have allowed Sigillaria to survive the drying of the great coal swamps that led to the extinction of many tree-sized lycopods during the middle of the Pennsylvanian Period (318 to 299 million years ago).
Sigillaria, lycopods, Lepidodendron