Sagittaria sagittifolia
NPPA pest plant
Biostatus
Exotic
Conservation status
Not applicable
Category
Vascular
Structural class
Herbs - Monocots
Simplified description
A tall marginal aquatic plant, with arrow-shaped leaves and submerged strap like leaves.
Flower colours
White
Detailed description
Tall summer-green perennial dying back to underground parts over winter. Emergent leaves have a distinctive glossy arrow-shape 3 -16 cm x 0.3-7 cm with long basal lobes 2-30 cm long. Petioles are triangular in cross-section. Plants can also produce ovoid floating leaves and strap-like submerged leaves. Rhizomatous with round tubers, up to 3 cm across, produced on these. No flowers seen on New Zealand material.
Similar taxa
Other Sagittaria species. Sagittaria montevidensis also has arrow-shaped leaves but petioles are D-shaped in cross-section and it does not produce creeping rhizomes or tubers. The two other Sagittaria species present in New Zealand (S. subulata and S. platyphylla) do not have arrow-shaped emergent leaves.
Distribution
Only field site from Coromandel Peninsula, Waikato, cultivated elsewhere.
Habitat
Still and slow flowing water bodies.
Detailed taxonomy
Genus
Family
Ecology
Flowering
No flowering plants seen in New Zealand
Year naturalised
2002
Origin
Native to Asia and Europe.
Reason for introduction
Ornamental pond plant and food plant (edible tubers)
Control techniques
Notify regional council if found
Life cycle and dispersal
Apparently by deliberate planting and subsequent spread by water movement. Possibly cultivated as a vegetable by some ethnic groups.
Other information
National Pest Plant Accord species
This plant is listed in the 2020 National Pest Plant Accord. The National Pest Plant Accord (NPPA) is an agreement to prevent the sale and/or distribution of specified pest plants where either formal or casual horticultural trade is the most significant way of spreading the plant in New Zealand. For up to date information and an electronic copy of the 2020 Pest Plant Accord manual (including plant information and images) visit the MPI website.
Referencing and citations
References and further reading
Champion et al (2012). Freshwater Pests of New Zealand. NIWA publication. http://www.niwa.co.nz/freshwater-and-estuaries/management-tools/identification-guides-and-fact-sheets/freshwater-pest-species.
Kasselmann C (2003). Aquarium plants. Krieger Publishing company, Florida, 518pp.
Attribution
Factsheet prepared by Paul Champion and Deborah Hofstra (NIWA).