Hymenophyllum lanceolatum Hook. & Am.

Common names: palai hinahina (gray fern)

Endemic

Latin lanceolatus, spearlike, alluding to the lanceolate shape of the frond.

Plants delicate, mostly epiphytic. Rhizomes threadlike, 0.1-0.5 mm diam. Stipes dark brown, bases with uniseriate, dark, unbranched hairs. Fronds 2.5-16 x 1-2.5 cm. Blades lanceolate, 2-pinnate-pinnatifid to 4-pinnate-pinnatifid, tips often nodding, pointed, dull, dark green, membranous but somewhat stiff, hairs scattered on margins and on veins, unbranched or 1-branched at their bases; rachises dark brown. Pinnae usually drooping, short-stalked, winged, pinna costae dark brown. Ultimate segments linear, about 1 cm wide, obtuse-tipped. Veins unforked, prominent, dark. Sori marginal at tips of ultimate segments. Indusia bivalved and immersed in tips of ultimate segments.

Colony-forming epiphyte on tree trunks and logs in wet forest, 440-1,320 m, all major islands.

Sphaerocionium lanceolatum may be dis-tinguished from S. obtusum by its nodding, Lanceolate fronds, with the margins and veins lightly clothed with hairs that are mostly unbranched or branched only at the base. It may be distinguished from Mecodium recurvum by the presence of hairs and by its dark brown stipes, rachises, costae, and veins.