Synonym(s): Polypodium spectrum Kaulf.; Co/ysis spectrum (Kaulf.) J. Sm.; Drynaria spectrum (Kaulf.) J. Sm.; D. thouinianum (Gaudich.) Fee; Phymatodes spectrum (Kaulf.) C. Pres!; Pleopeltis spectrum (Kaulf.) T. Moore; Polypodium spectrum var. ovatum Hillebr.; Po. thouinianum Gaudich.

Common names: pe'ahi (see discussion of the name laua 'e under Phymatosorus grossus)

Endemic                                            

Latin spectrum, vision, apparition, probably alluding to the frond's beauty.

Plants small to medium-sized, vinelike, creeping, terrestrial, becoming epiphytic. Rhi-zomes long-creeping, tips densely clothed with dark, deciduous scales, phyllopodia present. Fronds 10-50 cm long, 3-8 cm apart. Stipes with 14-15 vascular bundles arranged in a circle. Blades deltate to hastate with 3 lobes (sometimes 5-lobed on Kaua'i), additional small basal lobes occasionally seen, thin, chartaceous. Veins prominent, distinct, anastomosing to form equal-sized areoles with free, branched or unbranched, included veins. Sori round, small, 1-2 mm diam., scattered irregularly over adaxial surface of blade, mostly on tips of included veins in areoles.

Occasional terrestrial, epiphytic, or epi-petric ferns in mesic to wet forests, usually a ground cover with some parts ascending tree trunks, 180-1,050 m, all major islands. Microsorum spectrum is absent from some of its previous habitats, especially on O'ahu. It may appear as 1 or 2 fronds, or it sometimes spreads in a creeping, vinelike fashion.

A rare, malformed, pinnate form with 9-11 lobes of various sizes is known from a single colony on Maui.

The beautiful Microsorum spectrum may be recognized by its usually triangular fronds (palmately 5-lobed on Kaua'i) that are well separated on long, slender, creeping, often climbing rhizomes; prominent veins joining together to form areoles; and small sori on veins included in the areoles.