1. Cheilanthes pringlei Davenport, Bull. Torrey Bot. Club. 10: 61. 1883.
Pringle's lip fern
Stems long-creeping, 1--3 mm diam.; scales uniformly brown or with poorly defined, dark, central stripe, linear-lanceolate, straight to slightly contorted, loosely appressed, usually persistent. Leaves clustered to somewhat scattered, 4--15 cm; vernation noncircinate. Petiole dark brown, grooved distally on adaxial surface. Blade ovate-deltate, 3-pinnate-pinnatifid at base, 1.5--5 cm wide; rachis grooved adaxially, with scattered, lanceolate scales, not pubescent. Pinnae not articulate, dark color of stalk continuing into pinna base, basal pair conspicuously larger than adjacent pair, inequilateral, basiscopic pinnules enlarged, appearing glabrous adaxially. Costae green adaxially for most of length; abaxial scales multiseriate, lanceolate, truncate or subcordate at base, without overlapping basal lobes, conspicuous, the largest 0.4--0.8 mm wide, loosely imbricate, not concealing ultimate segments, erose, not ciliate. Ultimate segments spatulate, not especially beadlike, the largest usually 2--3 mm, abaxially glabrous or with a few small scales near base, adaxially glabrous. False indusia marginal, weakly differentiated, 0.05--0.25 mm wide. Sori discontinuous, confined to apical or lateral lobes. Sporangia containing 64 spores. 2 n = 60.
Sporulating late spring--fall. Rocky slopes and ledges, usually on igneous substrates; 700--1200 m; Ariz.; n Mexico.
Cheilanthes pringlei is often confused with young, sterile plants of C . fendleri , but it is easily distinguished from the latter by having rachises that are grooved adaxially. This species appears to be restricted to the Sonoran Desert; records from Gila and Cochise counties, Arizona, and southern New Mexico are based on misidentifications.