Stems erect, 4--12 mm diam. Leaves monomorphic, evergreen, clustered, (15--)75--125(--200) cm. Petiole (5--)15--50(--100) cm × (1--)2--9(--12) mm, at base with tan (whitish when young), ovate, glabrous scales. Blade (8--)25--75(--100) cm, broadest at or near base, tapering gradually to pinnatifid apex. Pinnae (3--)10--32 × (0.5--)1--3(--4) cm, incised 3/4 or more of width; segments oblique, somewhat curved, basal segments elongate parallel to rachises or acroscopic segment of a pinna enlarged and dentate; proximal pair of veins from adjacent segments running to sinus or meeting margin just above sinus. Indument abaxially of hairs 0.2--0.8 mm and stalked glands 0.1 mm on costae, veins, and sometimes blade tissue; veins and costules adaxially glabrous, lacking glands. Sori round, medial to supramedial; indusia tan, usually hairy; sporangia glabrous or with stalked pear-shaped glands borne on sporangial stalks. 2 n = 144.

In limestone crevices in hammocks; 0--50 m; Fla.; s Mexico; West Indies in the Antilles; Central America; South America to s Brazil, nw Argentina.

Thelypteris patens var. patens is known in the flora from one collection made in 1905 from Dade County, Florida.