Practical information to identify and manage non-native, invasive plants and animals
The Quiet Invasion:
A Guide to Invasive Species of the Galveston Bay Area
Old world climbing fern, small leaf climbing fern
Lygodium microphyllum

USDA Symbol:LYMI
ITIS TSN:17984
Presence:Species of Concern
Habitat:Terrestrial
Native Range:Africa, Southeast Asia, South Pacific Islands, and Australia
Toxic Characteristics
This species is not known to be toxic.
Geographic Distribution
Currently only identified in Florida, but is an aggressive invader there.
Introduction Pathways
Introduced as an ornamental; first discovered naturalized in south Florida in 1965.
Specific Primary Habitats
Requires moist conditions to germinate. Can grow in either full sun or shade. Can thrive in the understory of forested swamplands and hammocks.
Identifying Characteristics
Fronds (fern leaves) take the appearance of long branching stems. True stems are underground rhizomes. Leaflets are roughly triangular in shape. Infertile leaves (on vegetative plants) are without teeth, while fertile leaves (on reproductive plants containing spores) are toothed and are pinnately compound. No flowers exist.
Reproduction Characteristics
Long-distance propagation is through spore dispersion from reproductive plants. A single fertile leaf can produce up to 20,000 spores. Spores can germinate within 6 days to 2 years. Local propagation is usually by vegetative fragmentation and budding.
Growth Characteristics
Old world climbing fern is a long-lived perennial vine-like fern that repeatedly grows back from rhizomes. It can reach 90 feet in length.
Ecological, Economic, or Social Impact
Old world climbing fern prefers growing up and over large stands of trees. This alters forest fires, creating a "fire ladder" which enables flames to reach much higher. Trees that withstand ground fires are often killed when fires reach the canopy.
Control
Glyphosate is the most effective herbicide, but unfortunately is not selective and will affect local vegetation. Biological control via an Australian pyralid moth is being studied.

Native Species Alternatives
Below is a list of alternative plants that are native to the area:
  • Southern maidenhair fern (Adiantum capillus-veneris)
  • Turks' cap (Malvaviscus arboreus)
  • American beautyberry (Callicarpa americana)
This species belongs to the following lists:
Images
To view a larger version of an image, click on the thumbnail.
Both kinds of leaves of the Old World climbing fern: Sterile, unlobed leaflets, and fertile, toothed leaflets (center). Photo courtesy of USDA ARS Archives, USDA Agricultural Research Service, www.forestryimages.org; Image Number 0002128.
Both kinds of leaves of the Old World climbing fern: Sterile, unlobed leaflets, and fertile, toothed leaflets (center). Photo courtesy of USDA ARS Archives, USDA Agricultural Research Service, www.forestryimages.org; Image Number 0002128.
Undersides of the Old World climbing fern leaves (right) contain spores which can create new plants. Photo courtesy of Peggy Greb, USDA Agricultural Research Service, www.forestryimages.org; Image Number 2308086.
Undersides of the Old World climbing fern leaves (right) contain spores which can create new plants. Photo courtesy of Peggy Greb, USDA Agricultural Research Service, www.forestryimages.org; Image Number 2308086.
Infestation of the Old World climbing fern smothering an entire cypress tree stand. Photo courtesy of Peggy Greb, USDA Agricultural Research Service, www.forestryimages.org; Image Number 2308087.
Infestation of the Old World climbing fern smothering an entire cypress tree stand. Photo courtesy of Peggy Greb, USDA Agricultural Research Service, www.forestryimages.org; Image Number 2308087.
Infestation of the Old World climbing fern smothering an entire cypress tree stand. Photo courtesy of Peggy Greb, USDA Agricultural Research Service, www.forestryimages.org; Image Number 2308088.
Infestation of the Old World climbing fern smothering an entire cypress tree stand. Photo courtesy of Peggy Greb, USDA Agricultural Research Service, www.forestryimages.org; Image Number 2308088.
Page Updated/Reviewed: 07/14/2010 8:33 AM
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