Vascular – Exotic
Dicotyledonous Herbs other than Composites
Sprawling submerged plant often floating just under the waters surface, with finely divided thread-like leaves with tiny round bladders (often black).
Restricted to Westland (Westport to Haast).
Colonises acidic shallow water in lowland bogs, fens and pakihi.
Perennial, free-floating aquatic, often smothering other submerged plants or floating just under the waters surface. Stolons filiform, sparingly branched; stems up to 60 cm long, c. 0.5 mm diam., terete, glabrous, internodes
Utricularia australis(rare native species mostly in northern North Island) is superficially similar and at one time U. geminiscapa was mistakenly known as this species. The distribution ranges of these species do not currently overlap.
Summer to autumn
Summer to autumn
Water fowl spread seed. Accidental spread.
North-eastern USA and Canada
Reason for introduction
Likely to be accidental, possibly contaminated mining machinery
Not usually controlled in New Zealand.
Survives only in very wet places.
utricularia: A small bladder
Factsheet prepared by Paul Champion and Deborah Hofstra (NIWA).
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.
Heenan, P.B.; de Lange, P.J.; Knightsbridge, P.I. (2004). Utricularia geminiscapa (Lentibulariaceae), anaturalised aquatic bladderwort in the South Island, New Zealand. NZJ Bot 24: 247-251.
Salmon, B. (2001). Carnivorous plants of New Zealand. Ecosphere Publications, Auckland. 303 pp.