The Cordaites are a completely extinct group of gymnosperms with very characteristic, mostly long, strap-shaped leaves. This group includes large trees as well as shrub-like plants. The stems had well developed secondary wood and an internal cavity that was subdivided by horizontal septae. Infillings of this central cavity are known as Artisia. The fructifications consists of cone-like strobili with either seeds, or pollen sacs have been described as Cordaianthus. Although the foliage is rather uniform, cordaites are known to have occurred in various habitats, varying from mangrove-like environments to dry hinterland areas.
Cordaianthus
. - Collection Jens-Wilhelm Janzen.