How Paleozoic vines and lianas got off the ground: On scrambling and climbing Carboniferous-early Permian pteridosperms

Late Paleozoic pteridosperms displayed various growth habits, including arborescent, leaning, and scrambling and/or climbing forms. This article reviews information gathered to date on vine- and liana-like forms among these plants, based on impression/compression material and cuticle preparations from the Upper Carboniferous and Lower Permian of Europe and North America. Vine- and liana-like pteridosperms used various modes of attachment for both anchorage and support. Such adaptations are very similar (and perhaps analogous) to those that exist in extant angiosperms and include hooks, leaflet tendrils, tendrils terminating in adhesive pads, and aerial adventitious roots. A number of morphological features of scrambling/climbing pteridosperms (e.g., tiny, deeply sunken stomata, marginal water pits, various types of secretory structures, and heterophylly) are considered as they relate to the autecological significance where they may be related to special physiological requirements necessary in the scrambling/climbing growth habit. We hypothesize that scrambling and/or climbing pteridosperms may have played an important role in some of the late Paleozoic coal-swamp forest ecosystems, perhaps even comparable to the role of angiospermous vines/lianas in tropical and subtropical forest ecosystems today.