Global Invasive Species Database 100 of the worst Donations home
Standard Search Standard Search Taxonomic Search   Index Search

   Cardamine flexuosa (herb)
Ecology Distribution Management
Info
Impact
Info
References
and Links
Contacts

         Interim profile, incomplete information
    Taxonomic name: Cardamine flexuosa With.
    Synonyms: Cardamine hirsuta ssp. flexuosa (With.), Cardamine konaensis (St. John)
    Common names: wavy bittercress (English), wavy-leaved bittercress (English), wood bittercress (English), woodland bittercress (English)
    Organism type: herb
    Woodland bittercress, Cardamine flexuosa is a highly variable perrenial herb which flowers vigourously and forms dense root mats that can exclude other species. Seeds possibly remain viable in the seed bank for up to seven years requiring intensive management for control/eradication.
    Description
    A low but upright herbaceous plant, normally shorter than 30 cm but can grow taller in marshland. Stem arises from basal rosette of leaves that have about 5 roundish stalked leaflets on each side and a larger one at the end. Stem leaves are similar but smaller and often with narrower leaflets. Flowers are always white, and normally have 6 stamens (Framer, 2002). Ripe side pods are about 12 - 25 mm long and explode when ripe, dispersing seeds up to 500 m (Varnham, 2006). Usually perrenial but can be annual or biannual depending on environmental conditions.
    Similar Species
    Cardamine fallax, Cardamine hirsuta

    More
    Occurs in:
    agricultural areas, coastland, riparian zones, wetlands
    Habitat description
    Cardamine flexuosa is capable of growing in a variety of environments over a wide range of light and disturbance conditions (Kudoh et al., 1993). Capable of growing in a variety of soil types and acidities but requires it to be moist or wet. In Japan, Cardamine flexuosa is often found as an agricultural weed in paddy fields, crop fields and orchards (Kudoh et al., 1993).
    General impacts
    Cardamine flexuosa flowers vigourously and forms dense understory root mats (South Georgia Newsletter, 2004). These could potentially alter successional processes and displace native plant species. C. flexuosa is also known as a common agricultural weed in paddy fields, crop gardens and orchards (Kudoh et al., 1993).
    Uses
    The leaves and roots of Cardamine flexuosa can be eaten raw or cooked (Plants for a Future, 2008).
    Notes
    Cardamine flexuosa is sometimes regarded as a subspecies of Cardamine hirsuta (ITIS, 1998). Morphological resemblances are very strong and the two species are known to hybridise in the wild in Austria (Ellis & Jones, 1969).
    Geographical range
    Native range: The native range of Cardamine flexuosa is unclear due to its widespread distribution. While first described in Great Britain, it is also widespread in Europe west of Belarus and Ukraine as well as a few localities in the western part of Russia (Lihova et al., 2006). C. flexuosa has also been reported as native to northern Africa and southeastern Asia (Lihova et al., 2006).
    Known introduced range: Cardamine flexuosa has a widespread introduced range including North America, Australia and central Asia (Lihova et al., 2006). Asian range includes: Bangladesh, Bhutan, India, Indonesia, Japan, Kashmir, Korea, Laos, Malaysia, Myanmar, Nepal, Pakistan, Philippines, Sikkim, Thailand and Vietnam (eFlora, 2010).
    Introduction pathways to new locations
    Ignorant possession: Cardamine flexuosa was possibly transported in stores or footwear from the Falkland Islands where it grows abundantly. Seeds are sticky when wet and can be easily spread on clothing or animals.
    Natural dispersal: Cardamine flexuosa seeds are sticky when wet, and can be dispersed easily on clothes or animals. Thought to have been dispersed by ducks to the opposite the bay when discovered there in 2009. Also potentially spread far and fast in waterways, with the possibility of colonising any coastal drainage system along the warmer central north coast of South Georgia.
    Translocation of machinery/equipment: Cardamine flexuosa was possibly introduced to King Edward Point on vehicles brought in for rebuilding in 2000.


    Local dispersal methods
    Hikers' clothes/boots: Cardamine flexuosa seeds are sticky when wet and can be easily spread on clothing or animals.
    Natural dispersal (local): Cardamine flexuosa seeds are sticky when wet, and can be dispersed easily on clothes or animals. Thought to have been dispersed by ducks to the opposite the bay when discovered there in 2009. Also potentially spread far and fast in waterways, with the possibility of colonising any coastal drainage system along the warmer central north coast of South Georgia.
    Off-road vehicles: Cardamine flexuosa seeds are sticky when wet and can be easily spread on clothing or animals.
    On animals: Cardamine flexuosa seeds are sticky when wet and can be easily spread on clothing or animals.
    On clothing/footwear: Cardamine flexuosa seeds are sticky when wet and can be easily spread on clothing or animals.
    Road vehicles: Cardamine flexuosa seeds are sticky when wet and can be easily spread on clothing or animals.
    Water currents: Cardamine flexuosa seeds can potentially spread far and fast in waterways, with the possibility of colonising any coastal drainage system along the warmer central north coast of South Georgia.
    Management information
    Physical control: Digging out of Cardamine flexuosa appears to be the most effective form of control at present for the removal of plants and prevention or seeding (South Georgia Newsletter, 2008). Disposal of seed contaminated soils in the sea and weed matting have also been attempted, with a combination of spraying and weed matting reccomended for control on South Georgia at present (Varnham, 2006).

    Chemical control: Cardamine flexuosa is resistant to many types of herbicide. A recent study indicates that Weedol2 provides the best initial results while glyphosate gives longer lasting control (Varnham, 2006). As seeds may remain viable in the seed bank for up to seven years, continued spraying may be required for long periods of time (South Georgia Newsletter, 2005a).
    Reproduction
    Cardamine flexuosa is a hemaphrodite capable of self-pollination (Plants for a Future, 2008). Hundreds of small seeds are produced in small pods which explode when disturbed (Shanklin, 2006; Varnham, 2006) and can remain viable in the ground for up to 7 years (South Georgia Newsletter, 2005a).
    Compiled by: IUCN SSC Invasive Species Specialist Group (ISSG) with support from the Overseas Territories Environmental Programme (OTEP) project XOT603, a joint project with the Cayman Islands Government - Department of Environment
    Last Modified: Wednesday, 2 June 2010


ISSG Landcare Research NBII IUCN University of Auckland