Callitriche brutia var. hamulata
Common name
water starwort
Synonyms
Callitriche hamulata
Family
Plantaginaceae
Flora category
Vascular – Exotic
Structural class
Herbs - Dicotyledons other than Composites
Conservation status
Not applicable
Brief description
Aquatic linear underwater leaves, indented and often widened at apex, 8 to 20 mm long. Floating leaves in a rosette much broader. Flowers and fruit tiny, found at the leaf base.
Distribution
Kaipara Harbour and Marlborough.
Habitat
Shallow water of lake margins and drains.
Wetland plant indicator status rating
Information derived from the revised national wetland plant list prepared to assist councils in delineating and monitoring wetlands (Clarkson et al., 2021 Manaaki Whenua – Landcare Research Contract Report LC3975 for Hawke’s Bay Regional Council). The national plant list categorises plants by the extent to which they are found in wetlands and not ‘drylands’. The indicator status ratings are OBL (obligate wetland), FACW (facultative wetland), FAC (facultative), FACU (facultative upland), and UPL (obligate upland). If you have suggestions for the Wetland Indicator Status Rating, please contact: [Enable JavaScript to view protected content]
OBL: Obligate Wetland
Almost always is a hydrophyte, rarely in uplands (non-wetlands).
Detailed description
An aquatic glabrous (smooth/hairless) herb with submerged and floating leaves, or growing prostrate on damp mud. The submerged leaves are linear (single veined), 6 to 30 mm long and up to 1 mm wide, and deeply notched at the apex. The rosette forming, surface leaves are spathulate (spoon shaped) to ovate and have 3 veins. The flowers are solitary at the base of the leaves, without petals or seeals, and bract may be present (rarely). The fruit are sessile, pale green to dark grey/brown 1 to 1.4 mm wide with a very narrow wing running around the top and often the base.
Similar taxa
All Callitriche species are superficially similar and have variable vegetative parts (Lansdown 2008). Linear deeply notched submerged and circular fruit with reflexed styles and a very narrow wing are diagnostic for this plant.
Flowering
Spring/summer
Flower colours
Green
Fruiting
Summer to autumn
Life cycle
Plant fragments and seed.
Year naturalised
1959
Origin
Europe and North Africa
Reason for introduction
Probably a soil seed contaminant or contaminant of ornamental pond plants.
Control techniques
Can be controlled manually, mechanically or herbicidally depending on situation.
Tolerances
The taxonomy of the four introduced Northern Hemisphere Callitriche requires further investigation in New Zealand.
Etymology
callitriche: From the Greek kalli ‘beautiful’ and thrix ‘hair’, referring to the beautiful stems
Attribution
Factsheet prepared by Paul Champion and Deborah Hofstra (NIWA).
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.