Lygodium

Lygodium (climbing fern) is a genus of about 40 species of ferns, native to tropical regions across the world, with a few temperate species in eastern Asia and eastern North America. It is the sole genus in the family Lygodiaceae in the Pteridophyte Phylogeny Group classification of 2016 (PPG I). Alternatively, the genus may be placed as the only genus in the subfamily Lygodioideae of a more broadly defined family Schizaeaceae, the family placement used in Plants of the World Online . Per recent molecular evidence, Lygodiaceae is thought to have diverged relatively early from the other members of the Schizaeales due to the relatively high level of synonymous sequence divergence between the families within the Schizaeales.

==Description== Lygodium are unusual in that the rachis, or midrib, of the frond is thin, flexible, and long, the frond unrolling with indeterminate growth and the rachis twining around supports, so that each frond forms a distinct vine. The fronds may be from long, depending on the species. They are also easily identifiable by their possession of apical buds that lay dormant until damage to the rachis occurs, allowing them a high degree of endurance.