Cheilanthes leucopoda
Cheilanthes leucopoda Link
(Greek: leukos, white, and pous or podium, foot)
Local names: white-foot lip fern
Rhizomes compact; leaves clustered, 7–30 cm long; petioles straw-colored, shallowly grooved distally on upper surface; leaf blades elongate-pentagonal (due to larger basal pinnae with enlarged proximal basiscopic pinnules), 3–10 cm wide, 4-pinnate at base, the pinnae not articulate, the ultimate segments oblong to lanceolate, not beadlike, the largest 3–5 mm long, with long non-glandular hairs on both upper and lower surfaces; costae without scales on lower surfaces; false indusia weakly formed; 2n = 60 (Windham & Rabe 1993). Rocky slopes and ledges, on limestone substrates, sometimes locally abundant; Edwards (e.g., Correll 13451A, BRIT, TEX-LL), Uvalde (e.g., Correll 13459A, H.B. Parks s.n., 6 Jun 1938, BRIT), Real (e.g., J.L. Blassingame 2685, BRIT; Correll 13422, TEX-LL), and Kinney (Turner et al. 2003) cos. on the Edwards Plateau; in the U.S. known only from four counties on the Edwards Plateau of TX; also n Mexico. Sporulating summer–fall. Windham and Rabe (1993) noted that among the species covered in the Flora of North America treatment, this species is “unique in being a sexual diploid that consistently produces 32 spores per sporangium” [sexual species usually have 64 spores]. Recent molecular studies by Rothfels et al. (2008) show that it is actually more closely related to species of Notholaena than to Cheilanthes (the confusion caused by convergent evolution, which has resulted in distantly related species having superficially similar appearances)—nomenclatural changes will almost certainly be needed in the future (see further discussion under the genus Notholaena). Because of its limited distribution in the state, we consider this species to be of conservation concern in TX.