Native to Japan, tropical Asia, and Australia, Japanese climbing fern arrived in the American South as a curiosity and stayed as a catastrophe. Its lacy fronds spiral upward on twining rachises, reaching 90 feet into the forest canopy and forming dense mats at ground level that suppress native seedlings and smother understory shrubs. The rhizome system extends up to 10 feet underground, making it nearly impossible to eradicate by hand or fire.

Included here as a cautionary entry rather than a recommendation. Zones 7 through 13 in the Southeast are increasingly hospitable to this species as winters warm, and gardeners should treat any volunteer appearance as an emergency. It is listed as invasive by the North Carolina and South Carolina invasive plant councils and classified as a noxious weed in Florida. Native climbing fern (Lygodium palmatum) offers a gentle, legal alternative for those drawn to the form.