Contribution to knowledge on ontogenetic developmental stages of lepidodendron mannebachense presl 1838

Abstract

A new reconstruction of Lepidodendron mannebachense is proposed here based on collection of well-preserved compressions from middle Moscovian volcanoclastics of the Radnice Basin, Czech Republic. These specimens that represent remains of juvenile and matured individuals make progress in our current knowledge on ontogeny of this species and help us to improve its whole plant reconstruction. The juvenile stage was characterised by an unbranched columnar stem. The mature stage of L. mannebachense had an umbrella-like canopy produced by combination of more or less isotomous apical dichotomies of the stem and main branches with anisotomous pseudomonopodial branching. Dichotomous branching built the frame of the crown and continued until the limit for meristem division was reached. However, most of thin terminal shoots were anisotomous lateral branches growing from the main dichotomies. Some of them as well as terminal branches bore cones on their tips. Only a narrow zone of leaves was maintained at any stage of tree development. In the mature stage, leaves were retained only at apical parts of terminal shoots. L. mannebachense was a monocarpic type of plant with a determinate growth.