Old World climbing fern
Lygodium microphyllum is an invasive exotic vine in Florida, native to Asia and Australia. Old World climbing fern is climbing into trees and shading out native vegetation in hundreds of acres in east-central Florida. Old World climbing fern has the ability to “resprout” from almost anywhere along each climbing leaf–yes, leaf. Dense growth of the plant can also be a fire hazard, frequently enabling small ground fires to reach into tree canopies where it can kill the growing branches. Invasive exotics can thus change the effects of physical processes in plant communities.
Old World climbing fern is a fern with climbing fronds. What looks like a stem is actually a climbing, freely branching, leaf (frond) which may become as much as 100 feet long. The leafy branches off the main stem are 2-5 inches long. Old World climbing fern has two types of leaflets on its climbing leaf. The leaflet with the simple (unlobed) outline is a normal vegetative leaflet. The more convoluted leaflet has sporangia along its margin, which produce spores leading to the development of gametophytes. Gametophytes are separate small plants that produce sexual cells, which unite to form an embryo and ultimately a new climbing fern. This alternating of vegetative and reproductive plants as separate generations is typical of most ferns. The reproductive plants (gametophytes) are usually very small, and rarely seen without considerable detective work.