Endemic

Named for the Sandwich Islands, an earlier name for the Hawaiian Islands.

Stipes straw-colored, thin, 0.5-1.5 mm diam. at base, glabrous, 1/3-1/2 frond length. Blades linear-triangular, tips acute, 12-35 x 14-25 cm; rachises not or minimally winged. Pinnae lanceolate to linear-triangular, tips acute, stalks 2-3.5 mm long-6 x longer, not or minimally winged. Pinnules and ultimate segments well separated, oblong to elongate, 3 x longer than wide, at oblique angle to costae, margins entire to crenulate to slightly dentate. Sori supramedial to submarginal. Indusia hoodlike, attached at base.

Rare on mesic forest slope~, 550-900 m, Kaua'i, O'ahu, Lana'i, and West Maui.

Cystopteris sandwicensis may be distin· guished from C. douglasii by its linear· triangular fronds; pinnae acute at tip; longer, unwinged pinna stalks; narrow, obliquely arranged pinnules; ultimate seg· ments with entire margins; and marginal to submarginal sori.