A. tutwilerae is a fertile allotetraploid, formed by the chromosomal doubling of a specimen of the sterile diploid A.

It is named in honor of Julia Tutwiler, who discovered the only known wild population at Havana Glen in 1873.

Asplenium tutwilerae is a small, compact, evergreen, rock-inhabiting fern that grows in individual clumps.

Both roots and stipes (the stalk of the leaf, below the blade) may sprout along the length of the rhizome, which is covered in scales near its upper tip.

The scales are translucent, but are covered with a dark clathrate (lattice-like) network,[2] giving them a stained-glass-like appearance.

Each rachis is similar in color to the stipe at the base, turning green and dull towards the tip of the leaf.

In fertile fronds, sori are covered with membraneous indusia, which are attached to the leaf blade at one edge.

The apical part of the frond slowly tapers to a tip; its edges range from lobed to very slightly serrated.

It resembled walking fern and had proliferating tips, but the basal portion of the leaf was sporadically and irregularly cut into sharp-pointed lobes (never pinnae) in a manner resembling Scott's spleenwort, and the edge of the long, drawn-out apical portion of the leaf had shallow undulations rather than being a smooth curve.

× ebenoides was in question, and the existence of this fertile population was felt by Lucien Underwood, among others, to be a strong argument against the hybridity of the species.

× ebenoides, inclusive of A. tutwilerae, was eventually conceded to be a hybrid, the distinction between the fertile population at Havana Glen and the sterile individuals elsewhere was not entirely clear until 1953.

The resulting sporophytes showed a number of differences when compared with the Alabama plants: they were lighter green, more delicate in texture, had wider and more regular blades, and had slightly but distinctly toothed edges.

Wagner argued that these changes reflected differences in genotype between the original A. platyneuron and A. rhizophyllum individuals that had given rise to the two populations.

[11] However, in 2007, Brian Keener and Larry Davenport published a treatment of the fertile individuals as a distinct species, which they named A. tutwilerae for the original discoverer.

[12] Asplenium tutwilerae is found growing on ledges of conglomerate, which contains siliceous pebbles in a matrix rich in iron, with a little calcium.

[12] While A. tutwilerae can, like A. rhizophyllum, form proliferating buds at the leaf tip, these are quite rare and play no significant role in its reproduction.

Young sporophytes, with a part of the gametophyte, were transferred to a sterile mixture of loam, bone meal, aged cow manure, crumbled plaster (to provide calcium), crushed charcoal, and gravel.