Lygodium japonicum | Japanese climbing fern | Raithneach dhreaptha Sheapánach
Regulated invasive species of Union concern under the European Regulation on the prevention and management of the introduction and spread of invasive alien species [1143/2014].
First reported in the wild
Not present in Ireland or Northern Ireland
Invasive species - risk of Medium Impact
Introduction pathways - 1
Escape from Confinement
Introduction pathways subclass - 1
Introduction pathways - 2
Introduction pathways subclass - 2
Contaminant nursery material
NAPRA Ireland risk assessed
Lygodium japonicum is a species of rhizomatous (spreads via a network of horizontally spreading appendages) vine that can reach up to 30 m in length (Invasive Species Ireland, 2021). The creeping rhizomes have black to reddish-brown hairs with stripes every 1cm (CABI, 2021). The fronds (long, divided leaf e.g. ferns) are long and are evenly divided along the vines (Global Invasive Species Database, 2021). The rachis (main axis of the leaf) can be hairy or glabrous (hairless) and can be 3-30 m long (CABI, 2021). It is pinnate (structure similar to that of a feather) with short stalks of 3-5 cm (CABI, 2021).
Depending on the climate, Lygodium japonicum can be evergreen, growing and reproducing all year round or can die off in the winter with just the stalks surviving the cold temperatures (Global Invasive Species Database, 2021).
Biodiversity - Due to its ability to grow in various environments such as sun or shade in damp, disturbed or undisturbed areas, Lygodium japonicum is highly competitive and can dominate an area with a dense ‘wall’ of biomass, resulting in the exclusion of native species that can no longer grow due to lack of light (Bohn et al., 2018).
Socio-economic - Lygodium japonicum can reduce access to various recreational activities such as hunting and hillwalking, resulting in a negative economic impact as people may not be able to use previously suitable sites for various recreational activities (Bohn et al., 2018).
Lygodium japonicum may be found in various habitats such as wetlands, grasslands, woodland, cultivated areas of gardens and parks, man-made drainage ditches and riverbanks (Bohn et al., 2018).
Lygodium japonicum reproduces in a manner typical of ferns, alternating between gametophyte and sporophyte generations (CABI, 2021). The gametophyte is the sexual phase of reproduction and sees the production of gametes (sex cells). The sporophyte generation is the asexual phase of reproduction and sees the production of spores. Spores produced by Lygodium japonicum are 64-80 mm (CABI, 2021). Lygodium japonicum is capable of self-fertilisation which may improve its ability to become naturalised in new areas (CABI, 2021). Sporophytes can reach sexual maturity within 5 weeks of germination therefore, Lygodium japonicum can reproduce relatively rapidly (CABI, 2021).
Mechanism of impact
Temperate Asia, Tropical Asia, Australasia
Apart from its native distribution mentioned above, Lygodium japonicum can be found in South Africa, North America and Australia where it is either listed as introduced or invasive (Bohn et al., 2018). It is not currently known to be present in the natural environment in Europe (Bohn et al., 2018).
Within its native regions of Asia and Oceania, Lygodium japonicum can be found in a variety of countries (mostly Asia) such as Bangladesh, Bhutan, Cambodia, China India, Indonesia, Japan, North and South Korea, Thailand and Vietnam, to name a few (Bohn et al., 2018). In Oceania, it is found in Papua New Guinea (Bohn et al., 2018).
Records submitted to Data Centre in 2022
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How can you help
CABI Invasive Species Compendium: https://www.cabi.org/isc/datasheet/31783
Encyclopaedia Of Life: https://eol.org/pages/597517
Invasive Species Ireland: http://invasivespeciesireland.com/species-accounts/potential/terrestrial/vine-like-fern
Global Invasive Species Database: http://www.iucngisd.org/gisd/species.php?sc=999#:~:text=Lygodium%20japonicum%20is%20a%20perennial,1-3cm%20below%20soil%20surface.
Bohn, K., Brundu, G., Chapman, D., Frohlich, D., Hutchinson, J., Miller, S.R., Van Valkenburg, J. and Tanner, R., 2018. Pest risk assessment for Lygodium japonicum (Thunb.) Sw. [online] Available at: <https://circabc.europa.eu/faces/jsp/extension/wai/navigation/container.jsp?FormPrincipal:_idcl=FormPrincipal:_id1&FormPrincipal_SUBMIT=1&id=cc50e252-c06a-4732-9c8d-e848eaf7db39&javax.faces.ViewState=T%2BMqO13sh9oHl7pHEwvlwy2ZG0CDkWi3OcqAvaLpac47FhohRQBuw4> [Accessed 8 Jul. 2021].
CABI, 2021. Lygodium japonicum (Japanese climbing fern). [online] Available at: <https://www.cabi.org/isc/datasheet/31783#todescription> [Accessed 8 Jul. 2021].
European Commission, 2017. Invasive Alien Species of Union concern. [online] Luxembourg. Available at: <https://ec.europa.eu/environment/nature/pdf/IAS_brochure_species.pdf> [Accessed 25 Jun. 2021].
Global Invasive Species Database, 2021. Lygodium japonicum. [online] Available at: <http://www.iucngisd.org/gisd/species.php?sc=999> [Accessed 8 Jul. 2021].
Invasive Species Ireland, 2021. Lygodium japonicum. [online] Available at: <http://invasivespeciesireland.com/species-accounts/potential/terrestrial/vine-like-fern> [Accessed 8 Jul. 2021].