Lygodium japonicum
Lygodium japonicum (Thunberg) Swartz, Climbing Fern, can still be found scrambling on grasses and shrubs on the banks at the southern end of Pepe'ekeo Scenic Drive north of Hilo (Wilson 2437, BISH). It is native to eastern Asia and is common in cultivation, from which it occasionally escapes. It was first collected in Hawai'i in 1936 and was described as being semi-established around an old garden. Lygodium japonicum has persisted north of Hilo but did not seem to have spread significantly or to have been particularly damaging. Recently, however, numerous new sites of it have been reported.
On 20 December 1998 Lygodium japonicum was discovered on O'ahu growing on the grassy hills above He'eia State Park (Staples1166, BISH). Other sightings of it have been made on the island of Hawai'i on the hill opposite the Astronomy Department building of the University of Hawai'i, Hilo (Palmer, pers. com.), and on O'ahu along the Ulu Paina trail, adjacent to Temple Valley, Kaneohe, as well as on another site in the same vicinity (Waters, pers. com.). In 2000, plants were found in Kaneohe, vounteering in gardens among cultivated and native plants (Gagne s.n., BISH; LAM). These populations should be monitored carefully to guard against its uncontrolled spreading. In the southeastern United States, this species grows over other vegetation and smothers it, resulting in its death.
