Polypodium hawaiiense Undew.; P. helleri Undew.; P. myriocarpum Hook.; P. pellucidum var. bipinnatifidum Hook.

Common names: 'ae, 'ae lau nui (large-leaved 'ae) (P. & E.)

Endemic

Latin pellucidus, clear, transparent, referring to the translucent venation.

Plants medium-sized, colony-forming, terrestrial, sometimes epiphytic. Rhizomes medium-to long-creeping. Fronds erect or spreading, distant to clumped, up to 55 cm long. Stipes scaly, scales limited to phyllopodia, brown to nearly black, margins toothed and with short hairs. Blades deeply pinnatifid (occasionally 1-pinnate-pinnatisect or fully 2-pinnate), oblong-triangular to narrowly oblong, coriaceous, lower lobes with or without wings at sinus bases, tips rounded to truncate, lobes 8-45 pairs, margins entire to crenate to sometimes pinnatifid, cartilaginous, with small, short, teeth facing toward tips, with or without transparent false veins between true veins and attached to the margins at small sinuses but not joining other veins, hairs on abaxial veins and blades rare (occasionally plentiful especially on var. acuminatum), short, round, 3-celled, tips round. Veins free, translucent, usually 3-forked, ending in club-shaped expansions short of margins. Sori usually submedial or occasionally medial.

Found in diverse habitats in mesic to wet forests, 150-2,135 m, all major islands.

This species is remarkably variable in habitat and morphology with occasional irregular, or 2-pinnate, unusual forms appearing. It is a member of the monophyletic, primarily temperate species group known as the Polypodium vulgare complex. Enzyme studies have shown a close relationship among the varieties and forms recognized here (with the exception of the rare var. acuminatum, which has not been studied).