TPP could not believe it, but there it was, Osmundastrum cinnamomeum, cinnamon fern with a new name! Dang, it's happened again! TPP active botanical life has exceeded another taxonomic name. Imagine what Linnaeus would think. As explained in here previously, cinnamon fern is the oldest confirmed species on Earth. It's fossils demonstrate that cinnamon fern was alive and well growing in Jurassic Park. Pretty amazing. Some of you many know the other two species, royal fern (O. regalis or O. spectabilis - depending if old world or from the Americas) and interrupted fern, O. claytoniana. The reason for the change is that cinnamon fern is sister group to all of the other members of this fern family, Osmundaceae. In other words the family is a single lineage and basal branch is cinnamon fern so it has an ancient common ancestry with all of the other ferns in this family, some of which are placed in other genera (e.g., Todea). Now you have two choices: one, every species in the family becomes a member of the genus Osmunda so there would be only one genus, or two, cinnamon fern gets renamed and you can see what choice was made. When the specific epithet cinnamomea got switched from Osmunda to Osmundastrum a change in Latin gender required a new ending - thus cinnamomeum, -a to -um. This will be annoying for some time to come. This may be the taxonomic outcome of such great longevity; everyone is your ancestor. Maybe it should have been named Methusosmunda.