Polypodium decumanum Willd.

  • Authority

    Proctor, George R. 1989. Ferns of Puerto Rico and the Virgin Islands. Mem. New York Bot. Gard. 53: 1-389.

  • Family

    Polypodiaceae

  • Scientific Name

    Polypodium decumanum Willd.

  • Description

    Species Description - Rhizome creeping, 9-20 mm thick (excluding scales), densely clothed with soft, lustrous, pale orange, linear-fiHform scales mostly 12-20 mm long, with sharply denticulate-ciliate margins. Fronds few (one or two), spreading or arching, 100-200 cm long; stipes shorter than the blades, 45-72 cm long, up to 1 cm thick, lustrous yellowish- to reddish-brown, glabrous. Blades broadly oblong, 55-125 cm long, 25-70 cm broad, deeply pinnatisect, terminating in a broad, elongate, apical segment; lateral segments 7-16 pairs, oblong-ligulate or lance-ligulate, 3-6(-7) cm broad, acuminate at apex, often slightly constricted above the dilated base, separate or joined by a nanow rhachis-wing 1-5 mm wide; margins narrowly cartilaginous, slightly undulate and distantly low-crenate with minutely toothed sinuses; veins regularly reticulate; costal areoles narrow- linear or not evident; costules numerous, parallel, 2-4 mm apart, connected by 5-7 arched cross-veins forming regular rows of areoles; areoles mostly with two or three included excunent veinlets joined at the tips; outermost areoles smaller, inegular, without included veinlets, terminating along the margin in an inegular row of very small adaxial hydathodes, these lacking calcareous scales; tissue firmly herbaceous, dark green, never glaucous. Sori small, round, usually in 5-7 rows, each sorus located at the junction of two or three intra-areolate veinlets.

    Distribution and Ecology - General Distribution. Greater Antilles except Cuba; Guadeloupe, Martinique, Trinidad, and continental tropical America from Mexico to Honduras, and from Colombia and Venezuela to Paraguay and Argentina. Distribution in Puerto Rico. Known from scattered localities near the southeast, north, and west coasts; recorded from Bayamon, Dorado, Humacao, Loiza, Luquillo, Manati, Mayagiiez, Naguabo, San Juan, and Vega Baja. Habitat. Most often epiphytic on Pterocarpus trees in coastal swamp-forest, rarely in shaded humus over silica sand, almost always near sealevel. Some of the older records pertain to localities now destroyed by urban development.

  • Discussion

    Fig. 94.

    Type. Hoffmannsegg, from Brazil {Herb. Willd. 19640, B).

    Syn. Phlebodium decumanum (Willdenow) J. Smith, J. Bot. (Hooker) 4: 59. 1841.

    Chrysopteris decumana (Willdenow) Fee, Mem. foug. 5: 265. 1852.