Slender lip fern

Stems compact to short-creeping, usually 4--8 mm diam.; scales often uniformly brown but at least some on each plant with well-defined, dark, central stripe, linear-lanceolate, slightly contorted, loosely appressed, persistent. Leaves clustered, 4--20 cm; vernation circinate. Petiole dark brown to black, rounded adaxially. Blade linear-oblong to lanceolate, 3-pinnate at base, 1--3 cm wide; rachis rounded adaxially, lacking scales, with dense monomorphic pubescence. Pinnae not articulate, dark color of stalk continuing into pinna base, basal pair usually smaller than adjacent pair, ± equilateral, appearing sparsely pubescent to glabrescent adaxially. Costae brown adaxially for most of length; abaxial scales absent. Ultimate segments round to slightly oblong, beadlike, the largest 1--3 mm, abaxially densely villous with long, segmented hairs, adaxially sparsely hirsute to glabrescent. False indusia marginal, weakly differentiated, 0.05--0.20 mm wide. Sori ± continuous around segment margins. Sporangia containing 32 spores. n = 2 n = 90, apogamous.

Sporulating late spring--fall. Calcareous cliffs and ledges, usually on limestone or sandstone; 100--3800 m; Alta., B.C.; Ariz., Ark., Calif., Colo., Idaho, Ill., Iowa, Kans., Ky., Minn., Mo., Mont., Nebr., Nev., N.Mex., Okla., Oreg., S.Dak., Tex., Utah, Va., Wash., Wis., Wyo.; n Mexico.

Cheilanthes feei is an apogamous triploid of unknown parentage. It has small, beadlike blade segments similar to those of subg. Physapteris , but most morphological characteristics suggest a clear relationship to members of subg. Cheilanthes (T. Reeves 1979). The species is most often confused with C . parryi , from which it can be distinguished by its thinner, sparser pubescence and smaller ultimate segments.