There are over 700 species in the genus Asplenium, the spleenworts. Much more rarely, walking fern hybridizes with two other common spleenworts of eastern North America. Unlike many other spleenworts, it is not particularly sensitive to soil pH. Unlike many other North American spleenworts, it can grow on soil as well as rock. However, many spleenworts are epipetric or epiphytic and difficult to cultivate. Neither black-stemmed spleenwort nor the other pinnate American spleenworts have dimorphic fertile and sterile fronds.