Endemic

Leucostegia, a genus of ferns, + Greek -oides, resembling, suggesting a resemblance to a fern in the genus Leucostegia.

Plants small. Rhizomes erect, scales deltate, 2-3.5 mm long, brown to dark gray, clathrate. Fronds clustered, 20-30 x 2-3 cm. Stipes short, maroon, shiny, with scattered fibrils 2 mm long. Blades 1-pinnate, lanceolate, stiff, coriaceous, tips probably pinnatifid (the 3 known collections of this fern lack good blade tips). Pinnae 20-25 pairs, sessile to adnate, bases truncate and tending to overlap rachises, margins smooth, entire to undulate, tips obtuse, middle pinnae 0.9-1.8 x 0.5-0.7 cm, basal pinnae reduced, appearing as short, rounded auricles. Veins free, most basal veins forked, usualy widely spaced. Sari 3-4 per pinna, short, linear, medial along veins, borne on upper portion of vein. Indusia green, membranous, opening outward.

Presumably extinct; last coiiected in 1879, when it was coiiected three times in the area of the present Makawao Forest Reserve on East Maui. There are only three existing herbarium specimens.

Diellia leucostegioides, which may be the common ancestor of the other Diellia species, is close to D. erecta in morphology but differs from the other Diellia species in having medial (not marginal) linear sori along its veins, as in Asplenium, a genus from which it was only recently transferred.

Diellia leucostegioides, a Maui fern, is probably extinct. If it still survives and is casually observed in the field, it will probably resemble a small, short-leaved Asplenium normale with medial sori and black stipes.