Western Water-starwort - profile

Indicative distribution

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Key:

known

predicted

The areas shown in pink and/purple are the sub-regions where the species or community is known or predicted to occur. They may not occur thoughout the sub-region but may be restricted to certain areas. ( click here to see geographic restrictions). The information presented in this map is only indicative and may contain errors and omissions.

Scientific name: Callitriche cyclocarpa

Conservation status in NSW: Not listed

Commonwealth status: Not listed

Profile last updated: 05 Oct 2023

Description

Western Water-starwort is an aquatic or amphibious plant. Its submerged leaves are linear and mostly one-nerved; upper emergent leaves are spoon-shaped, and three to five-nerved. Male and female flowers are found together in the angles where the upper leaves meet the stems (in the "axils"). In female plants, flowers are found in the lower axils. Flowers are accompanied by leaf-like processes called bracteoles.
A recent review of the genus Callitriche regarded Western Water-starwort as a synonym of the commoner Winged Water-starwort (C. umbonata). The review considered that the defining characteristic of the narrowly winged, non-bulbous fruit of C. cyclocarpa merely represents an immature state of the fruit of C. umbonata.

Distribution

In NSW only recorded at “The Gut” near Koraleigh, on the floodway from the Murray to Wakool River, about 26 km NNW of Swan Hill. A record made in 1991 from the Poison Water Holes Creek near Narrandera has not been confirmed. Also recorded in Victoria.

Habitat and ecology

It has also been found in Victoria in River Red Gum (Eucalyptus camaldulensis) open woodland with an open grassy understorey dominated by Warrego Grass (Paspalidium jubiflorum) along river banks, and with wallaby grasses (Austrodanthonia setacea and A. caespitosa) on ground less-frequently inundated.
Also known from Melaleuca freshwater coastal wetland in Victoria.
Has been recorded in NSW and Victoria growing in thick patches in floodwaters.
Flowering and fruiting in September and November.
Aquatic forms of this species are submerged, except for the floating extremities; terrestrial forms are prostrate or shortly erect.

Regional distribution and habitat

Click on a region below to view detailed distribution, habitat and vegetation information.

Threats

Plant associations of the inland watercourses, floodplains and discharge areas are highly vulnerable to grazing by domestic and feral animals, and the clearing, drainage, irrigation and dredging practices used in cropping and horticulture.
Changed flooding patterns have affected regeneration in some cases (particularly in Box and River Red Gum woodlands).

Recovery strategies

A Saving Our Species conservation project is currently being developed for this species and will be available soon. For information on how you can contribute to this species' recovery, see the Activities to assist this species section below.

Activities to assist this species

Inform land managers and land owners of its occurrence and seek to minimise or eliminate clearing, drainage, irrigation and dredging in areas where this species occur.
Undertake feral animal control where required.
Ensure that this species is considered in all planning matters on land that contains or may contain populations.
Monitoring studies in known populations.
Undertake experimental studies on the effects of flooding and grazing disturbance.
Investigations into regeneration including seed-set, germination and seedling survival.
Undertake base-line surveys to locate new populations and extend the ranges of known populations.

Information sources

Aston, H.I. (1977) Aquatic Plants of Australia. (Melbourne University Press, Melbourne)
Bean, A.R. (2007) A taxonomic revision of Callitriche L. (Callitrichaceae) in Australia. Austrobaileya 7(3): 545-554
Mason, R. (1959) Callitriche in New Zealand and Australia. Australian Journal of Botany 7: 295-325
Murray Catchment Management Authority and Office of Environment and Heritage (2012) New South Wales Murray Biodiversity Management Plan: A guide to terrestrial biodiversity investment priorities in the central and eastern NSW Murray catchment. (Murray CMA, Albury)
Porteners, M. and Robertson, G. (2003) Threatened Plants in Western New South Wales: Information Review. (NSW NPWS, Hurstville)

IBRA Bioregion	IBRA Subregion	Known or predicted	Geographic restrictions region

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