Asplenium adiantum-nigrum is a common species of fern known by the common name black spleenwort. It is found mostly in Africa, Europe, and Eurasia, but is also native to a few locales in Mexico and the United States.
This spleenwort has thick, triangular leaf blades up to 10 centimeters long which are divided into several subdivided segments. It is borne on a reddish green petiole and the rachis is shiny and slightly hairy. The undersides of each leaf segment have one or more sori arranged in chains.
In Hawaii, this native fern grows on cinder cones and lava flows, and it is present in Hawaii Volcanoes National Park.