Callitriche platycarpa
Biostatus
Exotic
Conservation status
Not applicable
Category
Vascular
Structural class
Herbs - Dicotyledons other than Composites
Simplified description
An erect amphibious, slender-stemmed perennial, growing up to 1m tall in shallow freshwater or creeping, prostrate and mat-like on damp ground. Apical rosettes of leaves frequently float on the water surface, submerged leaves narrow. The flowers are small, green and inconspicuous.
Flower colours
Green
Detailed description
The stems are threadlike and branched, up to ca 50 cm long. The leaves are opposite and may be submerged or floating. Submerged leaves are narrow 0.5 to 2.5cm long with 2 rounded leaf tip lobes. The floating leaves are oval (ca 1 cm wide), and may form rosettes on the water surface. The leaf bases are joined by a wing-like ridge. The flowers are small, without petals and sepal, but have 2 small white bracts (that act as petals). The flowers occur in the leaf bases. There are 4 tiny fruits per flower that are heart shaped ca. up to 1mm in size, and do not have a narrow winged margin.
Similar taxa
All Callitriche species are superficially similar and have variable vegetative parts (Lansdown 2008). Very similar to C. stagnalis only distinguished reliably by pollen characters (Lansdown 2008).
Distribution
Plalmerston North in drains.
Habitat
Shallow water lake margins and slow flowing streams.
Detailed taxonomy
Genus
Family
Endemic genus
No
Endemic family
No
Ecology
Flowering
Spring/summer
Fruiting
Summer to autumn
Year naturalised
1989
Origin
Native to Europe.
Reason for introduction
Probably a soil seed contaminant or contaminant of ornamental pond plants.
Tolerances
The taxonomy of the four introduced Northern Hemisphere Callitriche requires further investigation in New Zealand.
Control techniques
Can be controlled manually, mechanically or herbicidally depending on situation.
Life cycle and dispersal
Plant fragments and seed.
Other information
Etymology
callitriche: From the Greek kalli ‘beautiful’ and thrix ‘hair’, referring to the beautiful stems
Referencing and citations
References and further reading
Johnson PN, Brooke PA (1989). Wetland plants in New Zealand. DSIR Field Guide, DSIR Publishing, Wellington. 319pp.
Aston, H (1977). Aquatic plants of Australia. Melbourne University Press, 367pp.
Lansdown, R.V. (2008). Water-starworts (Callitriche of Europe) BSBI Handbook 2, London. 180 pp.
Attribution
Factsheet prepared by Paul Champion and Deborah Hofstra (NIWA).