RHIZOMES: moderately stout, deep-seated, very long-creeping, densely pubescent with multicellular hairs. LEAVES widely spaced, deciduous. PETIOLES: shorter than to about as long as the blade, grooved adaxially. BLADES: somewhat papery or leathery, broadly deltate, 2–4 times pinnately compound. PINNAE: pinnatifid, acuminate at the tip, with numerous lobes, variously pubescent. SORI: forming a more or less uninterrupted submarginal line. INDUSIA: of 2 types, curled pinnae margins forming pseudoindusia opposed to excurrent true indusia, these linear, often poorly developed. X = 52. NOTES: 5 spp., nearly worldwide. (Greek for “small fern”). The treatment here follows the recent classification of Pteridium to comprise 5 species, with a number of additional infraspecific taxa (Thomson et al. 2008). Many previous authors have followed Tryon’s (1941) treatment of a single species with a dozen infraspecific taxa. REFERENCES: G.Yatskievych and M.D. Windham , 2008, Vascular Plants of Arizona: Dennstaedtiaceae. CANOTIA 4 (2): 38–40.