A reassessment of the leafy shoots of Pennsylvanian-age arborescent lycopods

ABSTRACT The known fossil-species of upper Carboniferous (Pennsylvanian) arborescent lycopod leafy shoots are re-examined. The leaf characters used in species characterisation include size (length and breadth), angle of departure from the stems and the overall shape (straight, curved or S-shaped). Sometimes leafy shoots can be directly related to known species of stems that are defined on their surface features of leaf cushions as in Lepidodendron, Lepidophloios and Ulodendron, or directly on the stem surface as in Bothrodendron. They are also assessed in terms of the determinate growth pattern of the plants. A key is given to identify the fossil-species of leafy shoots described here.