The fern genus Todea is known from only two living species. Todea barbara L., known as the king fern, is native to South Africa, New Zealand, and Australia while Todea papuana H. is known only from Papua New Guinea. Species in the genus Todea, as Leptopteris, are distinct from other in Osmundaceae in that sporangia are born on laminar pinnules.
So far the fossil record of the genus Todea consists only of the permineralized rhizome T. tidwellii from the Lower Cretaceous of Vancouver Island, Canada.
- Jud, Nathan, Gar W. Rothwell, and Ruth A. Stockey (2008). "Todea from the Lower Cretaceous of western North America: implications for the phylogeny, systematics, and evolution of modern Osmundaceae." American Journal of Botany, 95:330-339.
- Hennipman, E (1968). A new Todea from New Guinea, with remarks on the generic delimitation of recent Osmundaceae. Blumea 16: 105-108