Climbing fern - Definition and Overview

Lygodium, the Climbing Ferns
Lygodium japonicum
Scientific classification
Kingdom: Plantae Division: Pterophyta Class: Pteridopsida Order: Schizeales Family: Lygodiaceae Genus: Lygodium
Species
Lygodium palmatum - American climbing fern Lygodium japonicum - Japanese climbing fern Lygodium microphyllum

The Climbing Ferns are an unusual group of plants (Genus Lygodium) of tropical zones, with one temperate and one subtropical species. They are unique among plants in that the rachis, or midrib, of the frond (leaf) 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 three to ten meters long, depending on the species.

The one temperate species, the American Climbing Fern, Lygodium palmatum (shown in photograph below), is rare throughout its range in the United States and requires intensely acid soil. Two other species—Lygodium japonicum and Lygodium microphyllum—on the other hand, are exotic weeds throughout the deep south of the U. S., growing in a variety of soils. Lygodium japonicum is sparsely naturalized in Hawai'i.

Habit of the American Climbing fern, Lygodium palmatum