Pteris viridis Forssk.; Pellaea viridis (Forssk.) Prantl

Naturalized Green cliff brake

Latin viridis, green.

Rhizomes short-creeping, scales light brown to black with dark midrib and light margins. Fronds 25-80 cm long. Stipes closely spaced, round at base, flattened distally with mar-ginal ridges, dark brown to blackish, mostly glabrous. Blades 2-pinnate to 2-pinnate-pinnatisect, lanceolate to ovate-triangular, 24-60 x 12-27 cm, tips similar to a pinnule, not pinnatifid; rachises and costae dark brown to black, shiny, grooved with marginal tan ridges, grooves continuous between rachis and costae. Pinnae 10-19 pairs, to 15+ cm long, stalked, again 1-pinnate to 1-pinnate-pinnatisect, lanceolate, tips obtuse, similar to lateral pinnules. Pinnules 2-6 pairs per pinna, short-stalked, linear-triangular, mostly glabrous, bases hastate, margins entire, slightly revolute, apexes acute to obtuse, basiscopic pinnules larger than acroscopic one. Veins free, forked, distinct, anastomosing to form marginal commissural veins. Sori continuous over marginal commissural veins. False indusia continuous, thin, delicate, crenulate, opening toward costae.

Occurring in diverse habitats, most common in dry exposed areas, 10-700 m, on Kaua 'i, O'ahu, Maui, and Hawai'i, and probably present, but not yet reported, on other islands.

Cheilanthes viridis, a native of southern Africa, was found escaped from cultivation and first collected in Hawai 'i in 1928. Although it is variable with many varieties in its native range, the Hawai 'i plant is quite uniform. Recent DNA and morphologic studies have shown that this species is not related to species in the genus Pellaea.

Cheilanthes viridis, a 2-pinnate fern, may be distinguished by its linear-lanceolate fronds; dark brown to black stipes; flattened to minimally grooved, ribbed rachises; lower pinnules larger than the upper ones; and long, narrow, marginal sori covered by revolute margins.