Boston ferns, sword ferns

Greek nephros, kidney, + lepis, scale, in reference to the kidney-shaped indusia.

Plants medium-sized, terrestrial or epiphytic. Rhizomes decumbent to erect, short, bearing peltate scales, producing long stolons. Fronds clustered, erect, arched, or drooping. Stipes close to clustered, usually short in comparison with frond length, not articulate with rhizome. Blades 1-pinnate, long and narrow to short and obtuse, sometimes dimorphic with fertile pinnae narrower and shorter or longer than sterile ones; rachises grooved adaxially, glabrous or with abundant short scales, white hairs, or hairlike scales. Pinnae sessile to shortstalked, jointed at base, often detaching from rachises, costae adaxially grooved, scaly, hairy or not, white spots often present adaxially at vein tips, basal pinnae usually smaller, often abscising with age. Veins free, simple or forked. Sari medial to submarginal, round. Indusia kidney-shaped, attached at base, opening at 45° angle or toward pinna tips.

Nephrolepis contains about thirty often poorly defined species found in the Tropics and subtropics, especially in southeastern Asia. Represented in Hawai 'i by one indigenous species, one endemic subspecies of an indigenous species, three naturalized species including two cultivars, and two hybrids.