Kew Bull. 1932: 309. 1932.
Stems short-creeping, 4–10 mm diam. Leaves monomorphic, evergreen, ca. 65–200 cm or more. Petiole tan, (25–)40–120 cm × 4–10 mm, at base with scales absent or ephemeral. Blade 40–100 cm or more, gradually reduced distally with lanceolate apical pinna that is 1/4 to equaling longest lateral pinna; buds sometimes present at base of proximal pinna. Pinnae lanceolate, 15–25 pairs, (10–)15–25 × (1.5–)2.5–3.5(–4.5) cm, rounded to truncate at base, margin hooked-serrate; main lateral veins of fertile pinnae 3–5 per cm, with rows of 10–18 areoles between costa and margin, cross-veins somewhat curved. Indument abaxially of spreading, irregularly crimped hairs ca. 0.2–0.3 mm on costae and sometimes veins adaxially; blades glabrous adaxially. Sori oblong-arcuate, uniseriate between main lateral veins on cross-veins, often appearing confluent at maturity; indusia lacking; sporangia glabrous. 2n = 72.
Habitat: Cypress sloughs and swamps
Elevation: 0–50 m
Fla., s Mexico, West Indies in the Antilles, Central America, South America to n Argentina.