Synonym(s): Asplenium densum Brack.

Common names: 'oali'i

Subspecies endemic

Greek trichos, hair,+ manes, a kind of cup, possibly alluding to the cuplike cluster of shiny, black stipes, suggesting hair, at the base of the plant. Latin densus, thick, crowded, close, probably alluding to the dense clump of old stipes on the rhizome.

Plants small, terrestrial, with clustered fronds. Rhizomes short, erect, retaining many dark brown, shiny, old stipe bases. Fronds. 7-30 x 0.5-1.5 cm, never proliferous. Stipes wiry, dark brown to black, 2.5-10 cm long, shiny, glabrous, adaxial surface flat, with 2 greenish ridges on either side. Blades 1-pinnate, linear, narrowed below, subcoriaceous. Pinnae 15--45 pairs, almost sessile, alternate, ovate to round, to slightly dimidiate (part above costule larger), basal pinnae smaller and more widely spaced, distal margins crenulate. Veins inconspicuous, unforked. Sori 1--4 on each side of midribs of all pinnae.

Locally abundant in full sunlight in open areas on lava fields and in kipuka, 1,200-2, 700 m, on East Maui and Hawai 'i.

Asplenium trichomanes is one of the most widespread of all ferns and is distributed through Europe, Eurasia, South Africa, North America, Australia, Taiwan, and Japan. It is usually associated with rocky habitats and has many subspecies.

A smaller, more delicate form that does not retain thick clusters of old stipes is found along shady trails in Polipoli Springs State Park on the slopes of Haleakala on East Maui.

Asplenium trichomanes subsp. densum, a small, 1-pinnate fern, may be recognized by its numerous small, ovate to round pinnae; clusters of numerous old stipes forming a dense mass in mature plants; stipes that are shiny, dark brown to black, with the upper surfaces flat with greenish ridges on either side.