What does it look like?
Hawaiian arrowhead is an herbaceous and aquatic perennial that is very similar to Sagittaria montevidensi - the difference being its production of rhizomes and tubers.
Flowers: Hawaii arrowhead flowers have three petals and three outer sepals. The petals are large and white, with a purple blotch at their base. They grow on a distinct stem from the plant's root. This plant is not known to flower in New Zealand.
Fruits & seeds: Round seed heads are produced with many flat seeds in winged sheaths. These seeds can float easily and travel great distances in moving water. This plant is not known to flower in New Zealand.
Roots: This plant produces stolons and rhizomes that spread in aquatic and wetland conditions, and the plant also produces tubers 2-5 cm long at the ends of root stems.
Stems: Are smooth and square or triangular-shaped.
Why is it a problem?
Hawaiian arrowhead is an invasive weed with the potential to block waterways and is not currently known to exist in Hawke’s Bay.
Control methods
For further advice, contact us on 06 835 9200.
More information
Hawaiian arrowhead is a National Pest Plant Accord species. It is illegal to sell, propagate or distribute Hawaiian arrowhead.
Related links
New Zealand freshwater pest watchlist
NPPA and the control of weeds | NZ Government
Management Programme
National Pest Plant Accord (NPPA)
The NPPA is designed to prevent the sale, distribution and propagation of a set list of pest plants (the Accord list) within New Zealand. If allowed to spread further, these pest plants could seriously damage the New Zealand economy and environment.
More informationUnwanted Organism
An unwanted organism is any organism that's capable of causing harm to natural or physical resources (like forests and waterways) or human health. A number of introduced pests in New Zealand are classed as unwanted.
Taxonomies
FamilyAlismataceae
TypePlants
GroupClimber
HabitatFreshwater
Management ProgrammeNational Pest Plant Accord (NPPA)Unwanted Organism
