We describe the morphology and anatomy of large cordaitalean trees, preserved in Pennsylvanian (Bolsovian) alluvial
deposits in southwest Newfoundland. Remains include more than one hundred calcite-permineralized stumps, trunks, and branches, including the largest cordaitalean trunk ever discovered, as well as common adpressed leaves. Reproductive organs are not preserved. We propose a sterile reconstruction of this tree based on directly attached organs and anatomical similarities between isolated, but facies-associated, organs. At V 48.5 m high, mature cordaitaleans were the tallest trees in the Pennsylvanian tropical zone, and consisted of a straight, unbranched trunk topped by a dark, shading canopy, similar in gross morphology to extant araucarian conifers. A comprehensive review of the taphonomic occurrences of these large cordaitalean remains suggests that they grew in alluvial fan and extrabasinal terrains across Euramerica, and represent the earliest widespread upland forests.