The shape of leaf blades in A. tutwilerae is quite variable. The leaves are green in color, not leathery (unlike some other Asplenium species), and both leaves and their rachides (central axes) are covered by hairs like those on the upper stipe. 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. Within the sori, 64 spores are borne in each sporangium. The species is tetraploid, with a sporophyte chromosome number of 2n = 144.
