LEPIDODENDRON

one of the most commonly encountered genera of extinct treelike club mosses, order Lepidodendrales, class (or subdivision) Lycopsida. Some of its species, prominent during the Late Carboniferous Period (ending 286 million years ago), exceeded 30 metres (100 feet) and 1 metre (40 inches) in diameter. It was named originally for twig and branch fragments. Other so-called form genera were subsequently constructed for other parts not known to belong definitely to Lepidodendron: cones (Lepidostrobus), leaves (Lepidophylloides, or Lepidophyllum), seeds (Lepidocarpon), and underground parts (Stigmaria). Later, as more complete specimens were discovered in each genus, many species were created to accommodate them.