× ebenoides is intermediate in morphology between its two parents, combining the long, narrow blade of A. rhizophyllum with a dark stem and lobes or pinnae similar to those of A. platyneuron.

× ebenoides is generally sterile, fertile specimens with double the number of chromosomes are known from Havana Glen, Alabama.

In 1902, Margaret Slosson hybridized A. rhizophyllum and A. platyneuron in pure culture to produce specimens effectively identical to A.

The leaf blades rise from a dark-colored, shiny stem, and show a variable and irregular pattern of cutting.

The stipe (the stalk of the leaf, below the blade) is shiny and reddish to purplish brown in color, from 1 to 10 centimeters (0.4 to 4 in) long, and lacks wings.

[1][2] The rachis (central axis of the leaf) is shiny and hairless, reddish or purplish brown at the base fading to green towards the tip.

[1] The sori, 1 to 2 millimeters (0.04 to 0.08 in) long, are covered by thin, whitish indusia with irregular, rounded teeth.

This hybrid is intermediate between its parents, bearing lobes in the basal part of the frond only, and with purple color extending up the rachis but not the stipe.

× crucibuli, an artificial hybrid between A. platyneuron and the Asian walking fern, A. ruprechtii, has narrower blades, deeply pinnatifid in the middle and becoming pinnate at the base.

[10] R. Robinson Scott was the first to identify the fern as a new species, based on specimens collected in 1861,[c] on the west bank of the Schuylkill River about 8 miles (13 km) above Philadelphia.

[3] As it was collected in an area where walking fern and ebony spleenwort (then known as Camptosorus rhizophyllus and Asplenium ebeneum, respectively) were abundant, and the fern appeared to be a hybrid between the two, Scott tentatively referred to it as Asplenium ebenoides[d] and sent specimens to prominent pteridologists to see if it was a new species.

Specimens sent to England in 1864 and intended for Thomas Moore never reached him, but a frond and a print were sent by Scott to Rev.

A large population of a fern morphologically indistinguishable from A. ebenoides was discovered in Havana Glen, Alabama by Julia Tutwiler.

[14] The Havana Glen population, in contrast, was too large and contained too many young plants to be sterile, and on these grounds, Lucien Underwood declared A. ebenoides to be an independent species and not a hybrid.

[20] In 1879, D. C. Eaton (who had since accepted the distinctness of the species), suggested that an experimenter should attempt to artificially cross A. ebeneum with Camptosorus rhizophyllus to see if A. ebenoides would be produced.

[22] Margaret Slosson was inspired by Davenport's work to undertake the experiment, as well as attempting a cross between two species of Aspidium (now Dryopteris).

[27] In 1953, Herb Wagner showed that the fertile population in Havana Glen was tetraploid, while ordinary Asplenium ebenoides was diploid.

Wagner and Whitmire attributed this to the fact that the presumed ancestral diploid at Havana Glen and those in Maryland had originated in separate hybridization events between A. platyneuron and A. rhizophyllum and that alloploidy might magnify genetic differences between the parental species.

[30]) Since then, phylogenetic studies have shown that Camptosorus nests within Asplenium,[31][32] and current treatments do not recognize it as a separate genus.

[33] In 2007, Brian Keener and Lawrence J. Davenport described the fertile Havana Glen population as a separate species, Asplenium tutwilerae.

They argued that as the fertile population is sexually reproducing, reproductively isolated, and emerged from a common origin (in contrast to A.

× ebenoides, which arises through independent hybridization events, possibly followed by vegetative propagation), it is consistent with several well-accepted biological species concepts and is deserving of recognition.

[38] An epipetric fern, Asplenium × ebenoides can be found growing on a variety of rocks where the ranges of its parent species overlap.

Recommendations for best growth include moist potting mix,[41] or soil enriched by rock chips.