Stems short-creeping to nearly erect; scales dark reddish brown, concolored, margins entire or minutely denticulate. Leaves arching or pendent, densely clustered, 20--62 cm. Petiole 0.8--1 mm diam., glabrous, occasionally glaucous. Blade ovate, pinnate, 15--38 × 8--26 cm, gradually reduced distally, hirsute; proximal pinnae 3--4-pinnate; rachis straight or becoming flexuous, glabrous, not glaucous. Segment stalks 1--4 mm, dark color ending ± abruptly at segment base. Ultimate segments transversely oblong, nearly round, or fan-shaped, about as long as broad; base truncate or cuneate; margins of fertile segments crenulate or entire, sterile segments with margins serrulate; apex rounded. Indusia transversely oblong or crescent-shaped, 0.5--4 mm, covered with whitish needlelike trichomes. Spores mostly 35--53 µm diam. Sporulating late winter--early spring. Moist, shaded, limestone cliffs along streams and rivers, on boulders in creeks, and among rocks on steep slopes; 200--500 m; Tex.; Mexico; Central America in Guatemala, Belize. Adiantum tricholepis occurs in the flora only in Bandera and Medina counties on the Edwards Plateau in central Texas. Collections identified as A . tricholepis from the mouth of the Pecos River are Adiantum capillus-veneris .