Aspidium glabrum (Brack.) Mett. var. pusillum Hillebr.; Dryopteris parvula W. J. Rob.; D. parvula f. minuta Skottsb.; D. tenebrosa W. H. Wagner

Endemic

Latin pusilla, very small, tiny, puny, referring to the small size of the mature plant.

Plants small, terrestrial. Fronds at maturity only 4-30 cm long, often densely clustered, up to 35 per plant including old fronds, glabrous to slightly to moderately glandular, fertile when very small. Stipes very thin, less than 0.5 mm diam. at bases. Blades linear-lanceolate to oblong-lanceolate, 2-(3-) pinnate, rachises winged. Ultimate segments 0.5 x 1.4 mm. Sori marginal to submarginal, present on very small fronds. Indusia small.

Found in deep shade on rocky, steep, very wet, mossy stream banks. Known from the Koke'e area of Kaua'i at about 1,200 m elevation, but has been found on other islands. Its distribution is not well known. Plants intermediate between this variety and var. glabra are found.

Dryopteris glabra var. pusilla, a small fern of wet, dark habitats, may be recognized by its minute, but fully fertile, clustered fronds.