Species

Callitriche brutia var. hamulata

Etymology

Callitriche: From the Greek kalli 'beautiful' and thrix 'hair', referring to the beautiful stems

Common Name(s)

water starwort

Authority

Callitriche brutia var. hamulata Koch

Family

Plantaginaceae

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.

Flora Category

Vascular - Exotic

Structural Class

Dicotyledonous Herbs other than Composites

Synonyms

Callitriche hamulata

Distribution

Kaipara Harbour and Marlborough.

Habitat

Shallow water of lake margins and drains.

Features

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

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.

Life Cycle and Dispersal

Plant fragments and seed.

Tolerances

The taxonomy of the four introduced Northern Hemisphere Callitriche requires further investigation in New Zealand.

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.

This page last updated on 21 Aug 2013