SIGILLARIA

a genus of extinct treelike club mosses, order Lepidodendrales (class Lycopsida). Dating from the Carboniferous Period (360 million to 286 million years ago), it resembled Lepidodendron but differed in the form and pattern of leaf scars and in cone structure. It had a single trunk (or was sparsely branched), a terminal cluster of grasslike leaves, and a conspicuous pattern of spirally arranged leaf bases. Stem impressions are widely found, but petrified remains are less common.