Japanese Climbing Fern Lygodium japonicum
University of Florida, IFAS, Center for Aquatic Plants	St. Johns River Water Management District

Japanese climbing fern (Lygodium japonicum) is an invasive exotic vine in Florida, native to eastern Asia. Like its cousin, Old World climbing fern, Japanese climbing fern can overtop forest trees, thus shading-out and killing them. It is often found as a tangled mass over shrubs and fencelines, smothering ground cover and tree seedlings. Japanese climbing fern is already naturalized throughout the southeastern U.S. In Florida, it occurs north of Broward and Highlands counties.


Even though its leaflets are killed by winter frost, the rhizomes live on. It is believed to prefer damp places. Its reproductive spores, like those of other ferns, can be transported long distances by wind and even by vehicles.


How To Identify Japanese Climbing Fern


Japanese climbing fern is a fern with climbing fronds. It could be confused with Old World climbing fern (Lygodium microphyllum); the leaflet shapes easily tell the difference. 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 4-8 inches long. The leaflets of Japanese climbing fern are lobed and dissected. Leaflets are on stalks. Some of the leaflets look somewhat compressed--these are the leaflets that produce two rows of sporangia along the margin. Sporangia produce spores which lead 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.

For more information and pictures about Japanese climbing fern, as contained in the Langeland/Burks book, Identification & Biology of Non-Native Plants in Florida's Natural Areas, download this Acrobat .PDF file.


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The UF/IFAS Assessment lists plants according to their invasive status in Florida. View the list here.

Click here to see the herbarium specimen image of the UNIVERSITY OF FLORIDA HERBARIUM DIGITAL IMAGING PROJECTS.

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