1. Polypodium triseriale Swartz, J. Bot. (Schrader).  1800(2): 26.  1801.   
Goniophlebium triseriale (Swartz) Pichi-Sermolli; Polypodium brasiliense Poiret
Stems  not whitish pruinose, slender to stout, 5--15 mm diam., taste unknown; scales brown, ovate-acuminate, symmetric, somewhat to strongly clathrate, margins somewhat lighter, entire.  Leaves  to 90 cm.  Petiole  slender to stout, to 7 mm diam.  Blade  broadly ovate, 1-pinnate at base, widest at or near base, to 60 cm wide, papery to almost leathery; rachis glabrous abaxially and adaxially.  Segments  (pinnae) linear to oblong, apex acuminate; proximal segments stalked to nearly sessile, distal ones slightly narrowed but broadly adnate at base, less than 35 mm wide; margins entire or slightly wavy; apex acute; midrib glabrous adaxially.  Venation  anastomosing with a regular series of 2--5 rows of areoles on both sides of costae.  Sori  in 1--3 parallel rows on both sides of costa, 0.5--3 mm diam., circular when immature.  Sporangiasters  absent.  Spores  less than 58 µm, verrucose, with surface projections less than 3 µm. 2 n  = 148.
Epiphytic; 0 m; Fla.; s Mexico; West Indies; Central America; South America to s Brazil, Bolivia.
Commonly found in montane tropical rainforests, the epiphytic Polypodium triseriale is quite distinct from and probably only distantly related to other North American members of Polypodium . It seems likely that spores are occasionally blown into southern Florida, probably from the West Indies, and plants develop as naturalized populations.