Problematic Plant Species : Top 39 - National Invasive Species ...

Azolla fi liculoides
Crassula helmsii
Lagarosiphon major
Elodea canadensis
© Paul Green
Hydrocotyle ranunculoides
Lemna minuta
© Paul Green
Lysichiton americanus
© Paul Green
Myriophyllum aquaticum
© Paul Green
Problematic Aquatic Species
The introduction of non-native invasive species is now a major cause of species extinction in freshwater systems
(Millennium Ecosystem Assessment, 2005).
Scientifi c Name Common Name
Aponogeton distachyos Cape-pondweed
Azolla fi liculoides Water Fern
Ceratophyllum submersum Soft Hornwort
Crassula helmsii New Zealand Pigmyweed
Egeria densa South American Waterweed
Elodea canadensis* Canadian Waterweed
Elodea nutallii Nutall’s Waterweed
Hottonia palustris Water-violet
Hydrocotyle ranunculoides Floating Pennywort
Lagarospiphon major Curly Waterweed
Lemna minuta Least Duckweed
Lysichiton americanus Yellow Skunk-cabbage
Myriophyllum aquaticum Parrot’s-feather
Nymphoides peltata Fringed water-lily
Sagittaria rigida Canadian Arrowhead
Table 2: Problematic aquatic plant species
Submitting a record
Accepted records must meet data standards defi ned by the National Biodiversity Data Centre. The mandatory
list below is the minimal information that constitutes a valid biological record. Any additional information may
also be submitted.
Data item Description
Taxon name The scientifi c name of the recorded taxon. An authority is not required but if available please supply
this.
Grid reference A six-fi gure grid reference, employing three digits in each coordinate, to determine a 100 m square. The
preferred format is:
Example: M518152 The minimum legal value is a tetrad: 2km x 2km square. When recording on private
land please ensure permission has been obtained.
Location A description of where the organism was observed. For example: “A kilometre north of Maam Cross”.
Date The date that the observation was recorded. The following date format is preferable: dd/mm/yyyy.
The minimum legal value is the year.
Recorder The name of the person(s) that made the observation.
Determiner Who verifi ed the identifi cation of the organism?
When submitting aquatic invasive records it would be very valuable to include whether the species was recorded in a
natural or man-made area and in a connected or isolated aquatic system. Records can be submitted through the National
Biodiversity Data Centre website: www.biodiversityireland.ie If you have any queries please contact either Dr. Una
Fitzpatrick, Project Manager, email: ufi tzpatrick@biodiversityireland.ie or Colette O’ Flynn, Research Offi cer, e-mail
cofl ynn@biodiversityireland.ie, National Biodiversity Data Centre, Beechfi eld House, WIT West Campus, Carriganore,
Waterford. Phone: (051) 306240. Records may also be submitted through the ISI website: www.invasivespeciesireland.
com/sighting/ Both websites have the Data Centres Excel template fi le for download and submission.
For more information on invasive species and submitting records please visit
the Data Centre’s website: www.biodiversityireland.ie
National Invasive
Species Database
PROBLEMATIC PLANT SPECIES

National Invasive Species Database
Problematic Plant Species : Top 39
Invasive alien plant species are species that have been introduced, generally by
human intervention, outside their natural range and whose establishment and spread
can threaten native ecosystem structure, function and delivery of services. Once
introduced, control, management, and eradication where possible, of invasive species
can be very diffi cult and costly; therefore early detection and reactive measures
are desirable. Currently invasive species records are not centrally maintained. In
response to this, the National Biodiversity Data Centre has established a National
Invasive Species Database that will provide centralised up-to-date information on
the distribution of invasive species in Ireland. This database will play a key role in
recording, monitoring and surveillance programs.
Once a valid biological record is received it will be publically displayed on the National
Biodiversity Data Centre’s web GIS mapping system. For every additional record that
is submitted, a clearer picture of the status of that invasive species in Ireland is
generated. Display of such data against the backdrop of additional GIS layers will
greatly enhance the information available to those involved in combating the threat
of invasive species in Ireland. The 39 species listed in this booklet are the initial focus
of record collection in the establishment phase of the database.
Why these Top 39?
This list includes species which are not extremely widespread but which are
considered a problem or a potential problem in Ireland. This list was initially
compiled by Sylvia Reynolds in June 2007 and was agreed by Dr. Matthew Jebb
of the National Botanic Gardens. An additional seven more widespread
species (*) have been added to ensure overlap with the plant species
recognised by the Invasive Species Ireland project as Ireland’s
most unwanted invasives. The inclusion of Cotoneaster
integrifolius is based on the recommendation of the
Clare Biodiversity Group.
Problematic Terrestrial Species
Scientifi c name Common name Habitat recorded in
Acaena anserinifolia Bronze Pirri-pirri-bur Gardens and rockery.
Acaena novae-zelandiae Pirri-pirri-bur
Acaena ovalifolia Two-spined Acaena
Carpobrotus edulis Hottentot-fi g Coastal cliffs, rocks, sand.
Cotoneaster integrifolius
Entire-leaved
Cotoneaster
Wet slopes, castle gardens, rough pastures, grassy areas and
woods.
Demesne woodlands, roadsides, by streams, sandstone quarry
and lowland pasture.
Rocky substrates, walls, lakeshores, roadsides, railway banks,
sand dunes, woodland and urban habitats.
Cyperus eragrostis Pale Galingale Waste ground, rock outcrops, gravel shores, and roadsides.
Fallopia japonica* Japanese Knotweed
Demesnes, parks, river banks, roadsides, waste ground,
rubbish tips and coastal islands.
Gaultheria mucronata Prickly Heath Acid soils, moorland, woodland, quarries and coastal habitats
Gaultheria shallon Shallon Parks and demesnes.
Gunnera tinctoria* Giant-rhubarb
Heracleum
mantegazzianum*
Giant Hogweed
Impatiens glandulifera* Indian Balsam
Juncus planifolius Broad-leaved Rush
Lagarus ovatus Hare’s-tail Sandy beaches
Boggy ground, damp pastures, ditches, roadsides and by
streams.
Damp ground along rivers and streams, roadsides, waste
ground, walls, rubbish tips
Damp ground, along rivers, streams and lake margins,
roadsides and waste ground.
Damp habitats, peaty and mineral soils, by streams, on lake
shores and marshy meadows.
Libertia formosa Chilean-iris Lake shores, along rivers and coastal cliffs.
Phormium tenax New Zealand Flax
Rhododendron ponticum* Rhododendron
Coastal habitats, on cliffs, waste ground, in dunes, damp
ground and by streams.
Drier lowland, upland bogs, rocky slopes, native and demesne
woodlands.
Rubus spectabilis Salmonberry Woodland, open ground, neglected gardens, and hedgerows.
Sarracenia purpurea Pitcherplant Bogs
Sasa palmata
Broad-leaved
Bamboo
Parks, demesnes and stream sides.
Senecio cineraria Silver Ragwort Cliffs, walls, railway banks and mainly coastal sites.
Sisyrinchium californicum Yellow-eyed-grass Marshy meadows, lake shores, damp grassland and ditches.
Spartina anglica* Common Cord-grass Intertidal mud fl ats
Stratiotes aloides Water-soldier Lakes, ditches and canals.
Table 1: Problematic terrestrial plant species
Information from the Habitat recorded in column, was obtained from Reynolds, S.C.P. (2002) A catalogue
of alien plants in Ireland. National Botanic Gardens, Glasnevin, Ireland.
Additional information on many of the Top 39 species in this booklet can be found on the Invasive Species
Ireland website: www.invasivespeciesireland.com which also has a colourful ‘Field Guide to Invasive
Species in Ireland’ available for download.