Stems creeping, 4--8 mm diam. Leaves monomorphic, evergreen, (0.5--)1--3.5 cm apart, (30--)65--140 cm. Petiole straw-colored, 15--70 cm × 2--7(--9) mm, at base with scales tan to brownish, linear-lanceolate, hairy at margin. Blade 30--70 cm, broadest at or near base, abruptly narrowed distally, apical pinna ± similar to lateral pinnae, 5--17 × 1--3(--5) cm. Pinnae (4--)10--22(--28) × (0.3--)0.7--1.5 cm, incised 1/2--3/4 of width; segments somewhat curved, margins revolute, those at base of proximal pinnae slightly elongate; proximal pair of veins from adjacent segments running to sinus. Indument abaxially of hairs 0.2--0.4 mm on costae, veins, and blade tissue, also of brownish scales 0.6--1.2 mm on costae; veins and blade tissue glabrous adaxially. Sori round, medial to supramedial; indusia tan, bearing hairs 0.2--0.4 mm; sporangia glabrous. 2 n = 144.

Limestone banks, in sun or partial shade; 0--50 m; Fla.; s Mexico; West Indies in the Bahamas, Cuba; Central America in Guatemala.

Thelypteris augescens occasionally hybridizes with T. kunthii and T. ovata var. ovata in southern Florida.