[Hillebrand's Polypodium pellucidum y var.]

Endemic

Latin acuminatus, pointed, sharpened, allud-ing to the rather pointed frond lobe tips. Blades deeply pinnatisect to fully 1-pinnate at base, with 2 to several lobes not winged to rachises, lobes up to 32 pairs, long, narrow, acuminate, margins regu-larly crenulate to crenulate-serrate, false veins absent, adaxial surfaces of lamina as well as costae and veins well covered with minute (0.1 mm long), 3-celled, round-tipped hairs. Veins often anastomosing to form few areoles at lobe bases, especially in lowest lobes. Sori medial.

Currently known only from isolated areas, 1,000-1,300 m, in the Waimea and Hanalei areas of Kaua'i, and the Kaupo Gap of Haleakala on Maui. Plants with characteristics between those of var. pellucidum and var. acuminatum are found. The minute hairs found in this variety are found in occasional scattered popula-tions of the usually glabrous var. pellucidum. In those populations the hairs may be scattered or numerous.

This probably rare, little-known, seldom-collected fern has not been closely studied and may well be worthy of recognition as a species.

Polypodium pellucidum var. acuminatum may be distinguished from var. pellucidum by fronds that are fully 1-pinnate at the bases and by long, narrow, pointed lobes. Veins at the bases of some lower pinnae or lobes join to form areoles; "false veins" are absent; and there are numerous short, 3-celled, round-tipped hairs on the under-surfaces of the fronds.