Endemic

Greek epi-, over, upon, on, + gaea, land, earth, referring to its habit of growing in mosses above the ground.

Plants similar to Adenophorus tamariscinus, epigeous in moss mats at tree bases or occasionally epiphytic on low branches. Rhizomes long-creeping, slender, 1-2.5 mm diam. Fronds erect, distant, mostly 8-18 cm long. Stipes 0.5-1 mm diam., 1/10-1/4 frond length, narrowly winged on each side of adaxial surface. Blades 2-pinnate, linear to sublinear, basal pinnae gradually reduced. Pinnules narrow, linear-lanceolate, aeroscopic basal pinnules often slightly en-larged and unequally 1-forked. Sori usually wider than ultimate segments.

Locally common in wet forests and bogs, 1,050-1,550 m, Kaua'i only.

Adenophorus epigaeus, a mid-to high-elevation bog and swamp species, found only on Kaua 'i, is the ecological equivalent of A. tamariscinus var. montanus of Moloka 'i, Maui, and Hawai 'i. Its long-creeping rhizome and slightly enlarged, forked, upward-facing basal pinnules suggest a relationship to A. tripinnatifidus, and its fronds resemble those of A. tamariscinus.

Adenophorus epigaeus, found only on Kaua'i, may be distinguished from A. tamariscinus by its thin, long-creeping rhizomes with narrow and well-separated fronds. The upward-facing pinnules at the pinna bases are usually larger and irregularly 1-forked.