Polypodium triseriale

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. 2n = 148.

Habitat: Epiphytic
Elevation: 0 m

Fla., s Mexico, West Indies, Central America, South America to s Brazil, Bolivia

Discussion

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.

Selected References

None.

Lower Taxa