Indigenous Latin cordis, heart, +folium, leaf; if inter-preted as "heart-shaped leaf," a puzzling ref-erence to the pinna shape of this fern.

Plants medium-sized, usually terrestrial, occasionally epiphytic. Rhizomes decumbent to erect, stolons with occasional attached underground tubers. Fronds erect to drooping, to 30-70 em long. Stipes 1/10-1/8 frond length, scales bicolorous, dark brown center with tan margins. Blades linear, width generally uniform except at base and tip. Pinnae 1-2.5 x 0.5-0.7 em, 2-6 x longer than wide, often deciduous with age, convex as seen from above, margins with a thin carti-laginous border, shallowly crenate to slightly toothed, tips obtuse, dentate, adaxial grooves of costae glabrous, basal auricles minimal to small. Sari medial to supramedial, depressed adaxially, forming convex elevations on adaxial surfaces. Indusia mostly opening toward pinna tips.

Locally common terrestrial or epiphyte in mesic to wet forests, 440-1,525 m, all major islands.

Nephrolepis cordifolia is the only Nephro-lepis in Hawai 'i that produces subterranean tubers on stolons. These tubers serve as both a storage organ and a reproductive unit, and can be used for propagation if removed with a small piece of stolon and potted.

This species is probably pantropical in distribution, but its taxonomy is confused and some authors apply the name N. auriculata (L.) Trimen to this or a very similar species. It is a common fern in horticulture, and the horticultural material may originate from sources outside Hawai 'i.

Nephrolepis cordifolia may be recognized by its narrow, linear blades of generally uniform width except at the bases and tips; convex pinnae; and indusia generally opening toward the tips of the pinnae. This is the only Hawaiian N ephrolepis with subterranean tubers occasionally attached to the stolons.