Whitefoot Lipfern

Description

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.