Indigenous                          Adder's tongue

Latin nudus, bare, naked, + caulis, stalk of a plant, probably referring to the lack of old stipe bases on the stem.

Rhizomes subterranean, subglobose, 3.5-6.4 mm diam., tips usually with more than 1 frond, lacking stubble of old stipe bases, up to 15 roots per plant, occasionally proliferous, about 0.5 mm diam., yellowish to pale brown. Fronds small, rarely more than 1.5 cm long, spreading, often flat on ground. Sterile blades ovate or lanceolate-ovate, apex acute to apiculate. Veins obscure, reticulate, forming areoles. Fertile spikes 5-10 x longer than sterile blades, occasionally short-branching, arising at ground level, with up to 12 pairs of sporangia at tips.

Uncommon to rare in Hawai 'i in lawns and grassy fields, 30-1,000 m, on Kaua'i, O'ahu, and around fumaroles in the Kilauea area on Hawai 'i. Up to seven varieties have been recognized in its wide distribution from the southern United States to Brazil, the Caribbean, Africa, tropical Asia, and Australia. His-torical collections suggest that this species is native to Hawai 'i, but it may be an early introduction.

Ophioglossum nudicaule may be recognized by its presence in lawns, grassy fields, and near volcanic fumaroles; small fronds spreading flat on the ground; and long, fertile spikes with usually fewer than 12 pairs of sporangia at tips.