Asplenium resiliens
Asplenium resiliens Kunze
(Latin: resiliens, jumping, springing back, or bending back, resilient, probably in reference “to the flexible petioles of this species”—Thieret 1980)
Local names: black-stem spleenwort, little ebony spleenwort
Rhizomes erect, not branched; leaves monomorphic, to ca. 35 cm tall, the blades linear to linear-oblong or linear-lanceolate in outline, usually more coriaceous than in A. platyneuron; petiole and rachis black, shiny; pinnae opposite or nearly so, subentire to crenulate, the basal auricle usually not overlapping the rachis; n = 2n = 108 (Wagner et al. 1993). Usually growing on rocks, typically limestone or granite; widespread in c TX and the Trans-Pecos, and disjunct n to Grayson Co. (W.F. Mahler et al. 10102, BRIT) and e to Orange (W.L. Bray 62, TEX-LL) and Angelina (Turner et al. 2003) cos.; across s 1⁄2 of U.S. from PA s to FL w to NV and AZ; also Mexico, Guatemala, and South America. Sporulating Apr–Nov. This species has an interesting distribution in TX; it is widespread in the Trans-Pecos and the Edwards Plateau (and adjacent areas) and then disjunct to 3 outlying locations. This distribution is presumably a reflection of the rarity of the necessary rocky substrates in large portions of TX. Asplenium resiliens is apogamous (= a type of asexual reproduction that does not involve fertilization; the sporophyte is formed directly from the gametophyte without gamete production— no swimming sperm are formed), which is often considered an adaptation for xeric environments (J. Peck, pers. comm.).