Polypodium crinale Hook. & Am.; Phegopteris crinalis (Hook. & Am.) H. Mann [Ctenitis crinalis in un-published checklists]

Common names: palapalai 'aumakua

Endemic

Latin crinalis, relating to hair, in reference to the hairy appearance of this species.

Plants medium-sized, appearing hairy. Rhizomes decumbent, short. Fronds erect, occasionally pendent, 20-85 cm long. Stipes 1/3-1/2 frond length, straw-colored, occasionally dark brown, heavily clothed with narrow, twisted, dark brown, hairlike scales and hairs. Blades 2-to 3-pinnate, ovate-lanceolate, dark green, subcoriaceous; rachises, costae, veins, and abaxial surfaces scaly (like stipes), but with progressively smaller scales. Pinnae 9-16 pairs, short-stalked basally to adnate distally, basal pinnae elongate-triangular, distal pinnae lanceolate, somewhat falcate. Basiscopic pinnules of lowest pinnae larger than acroscopic ones. Ultimate segments oblong, obtuse, regularly lobed with basal lobes the largest. Veins 1-to 2-forked. Sori adnate and medial on distal branches of vein forks, or raised on narrow, pale, vascularized stalks. Indusia absent.

Common in scattered locations in wet forests, usually in gulches and along streams, 300-1,900 m, all major islands. Very rare on O'ahu and absent from large parts of Hawai 'i Island. A smaller variety with indusia raised on stalks is found on Kaua'i.

Dryopteris crinalis, a 2-to 3-pinnate fern, lacks indusia and may be distinguished by its numerous narrow, twisted, dark brown, hairlike scales and hairs on the stipes, rachises, and pinnae under-surfaces.