Tags: Fern.
Cyathea cranhamii is an extinct species of tree fern. It was described based on permineralised sori from the Early Cretaceous deposits of Apple Bay in Vancouver Island British Columbia.C. cranhamii has sori arranged in two rows on narrow pinnules. They are covered by globose indusia which resemble those of Sphaeropteris species in morphology. Sporangia are circinate (ring-shaped) and bear multicellular stalks. They diverge from a basal vascular receptacle.