Utricularia geminiscapa
Common name
bladderwort
Family
Lentibulariaceae
Flora category
Vascular – Exotic
Structural class
Herbs - Dicotyledons other than Composites
Conservation status
Not applicable
Brief description
Sprawling submerged plant often floating just under the waters surface, with finely divided thread-like leaves with tiny round bladders (often black).
Distribution
Restricted to Westland (Westport to Haast).
Habitat
Colonises acidic shallow water in lowland bogs, fens and pakihi.
Detailed description
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
Similar taxa
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.
Flowering
Summer to autumn
Flower colours
Yellow
Fruiting
Summer to autumn
Life cycle
Water fowl spread seed. Accidental spread.
Year naturalised
1975
Origin
North-eastern USA and Canada
Reason for introduction
Likely to be accidental, possibly contaminated mining machinery
Control techniques
Not usually controlled in New Zealand.
Tolerances
Survives only in very wet places.
Etymology
utricularia: A small bladder
Attribution
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.