Asplenium rhizophyllum one collection on sandstone in the Shawnee Hills of Illinois. A triploid hybrid between walking fern and Tutwiler's spleenwort was accidentally produced in culture. A similar plant collected from limestone in Shepherdstown, West Virginia could have originated from the same parents, from an unreduced (diploid) gametophyte of Scott's spleenwort crossed with walking fern, or from an unreduced walking fern gametophyte crossed with ebony spleenwort. In 1813, Henry Muhlenberg listed lobed spleenwort as "Asplenium rhizophyllum" var. "pinnatifidum", although he did not provide a description distinguishing the variety from the typical species. It was described as the species "A. pinnatifidum" by Thomas
Acadia Cliffs State Nature Preserve The name derives from the fact that the land was formerly owned by the Acadia Coal Company. The property includes an old millstone quarry, and many old millstones can still be seen on the site, now back in the forest. This nature preserve was established in part to protect the Bradley's spleenwort, "Asplenium bradleyi", which grows there. The spleenwort is a state-listed plant species. Acadia Cliffs State Nature Preserve Acadia Cliffs State Nature Preserve is a state nature preserve in Washington County, Ohio, United States, with a small neck extending into Athens County, Ohio. Covering an area of , it