Naturalized

Latin ensis, sword,+ folium, leaf, probably in reference to a common frond shape in this genus.

Plants terrestrial. Rhizomes short-creeping. Stipes tan to dark brown. Blades 1-pinnate, tips the same as lateral pinnae, coriaceous. Pinnae 2-5
(-7) pairs, long and narrow, 5-17 x 0.3-1 cm. Veins reticulate. Sori linear, continuous along most of length of pinna margins, up to several cm long, protected by indusia opening outward.

First collected in Hawai 'i in 1969 near a fumarole in Hawai 'i Volcanoes National Park. Now found in mesic areas in extensive localized plots in scattered localities, 15-1,220 m, Kaua'i, O'ahu, Maui, and Hawai'i. Lindsaea ensifolia is native to Zimbabwe, Mozambique, Reunion, Madagascar, India, the Philippines, New Guinea, and the western Pacific.

Several plants of a remarkable intergeneric hybrid (x Lindsaeosoria flynnii) have recently been discovered in Kahili Mountain Park on Kaua 'i where this species grows and hybridizes with Sphenomeris chinensis (see Hybrids later in this genus treatment for details).

Lindsaea ensifolia may be recognized by its 1-pinnate fronds with tips resembling the lateral pinnae; 2-5 (as many as 7) pairs of long, narrow pinnae; netlike vein pattern; and long, continuous, marginal sori protected by long marginal indusia that open outward.