Callitriche macropteryx Hegelm., Callitriche microphylla Colenso
Vascular – Native
Herbs - Dicotyledons other than Composites
The National Vegetation Survey (NVS) Databank is a physical archive and electronic databank containing records of over 94,000 vegetation survey plots - including data from over 19,000 permanent plots. NVS maintains a standard set of species code abbreviations that correspond to standard scientific plant names from the Ngä Tipu o Aotearoa - New Zealand Plants database.
2n = 10
Current conservation status
The threat classification status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2017 using the New Zealand Threat Classification System (NZTCS) – more information about this can be found on the NZTCS website This report includes a statistical summary and brief notes on changes since 2012 and replaces all previous NZTCS lists for vascular plants. Authors: By Peter J. de Lange, Jeremy R. Rolfe, John W. Barkla, Shannel P. Courtney, Paul D. Champion, Leon R. Perrie, Sarah M. Beadel, Kerry A. Ford, Ilse Breitwieser, Ines Schönberger, Rowan Hindmarsh-Walls, Peter B. Heenan and Kate Ladley. Please note, threat classifications are often suggested by authors when publications fall between NZTCS assessment periods – a suggested threat classification status has not been assessed by the NZTCS panel.
2017 | Not Threatened | Qualifiers: SO
Previous conservation statuses
2012 | Not Threatened
2009 | Not Threatened
2004 | Not Threatened
Indigenous. In New Zealand known from the Kermadec, Three Kings, North, South, Stewart and Chatham Islands. Also in Australia.
Coastal to montane in damp, muddy ground or in shallow seasonal pools, along lake and stream sides. Often in dense forest.
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).
FACW: Facultative Wetland
Usually is a hydrophyte but occasionally found in uplands (non-wetlands).
Short-lived perennial to annual herb forming matted patches. Stems filiform, much-branched, up to 200 mm long when submerged usually much less above water. Leaves on filiform petioles up to 3 mm long; lamina 2-5 x 1-5 mm, bright green, rhomboid to suborbicular, membranous, apex acute, cuneately narrowed to base, margins usually with 1-2 prominent teeth. Flowers in axils, with male and females together or solitary; shortly pedunculate, ebracteate; stamens and styles very hsort. mericarp obovate, laterally compressed, 1.0-1.3 mm long; surfaces dull, reticulate or with a raised central part in each cell, body red-brown, dark red-brown or dark brown or light brown to grey-brown, with a pale orange-yellow to light orange-yellow wing.
Not easily confused with other indigenous or naturalised species of Callitriche. The rhomboidal toothed leaves in particular readily distinguish this species from the others.
October - December
November - March
Mericarps possibly by water and attachment (Thorsen et al., 2009).
Easily grown from rooted pieces and seed. Can become invasive but makes a pleasant ground cover in shaded, poorly drained soils.
callitriche: From the Greek kalli ‘beautiful’ and thrix ‘hair’, referring to the beautiful stems
muelleri: Named after Baron Ferdinand von Mueller, 19th century German/Australian botanist and founder of the National Herbarium of Victoria
Fact sheet prepared by P.J. de Lange for NZPCN (1 June 2013).
References and further reading
Thorsen, M.J.; Dickinson, K.J.M.; Seddon, P.J. 2009. Seed dispersal systems in the New Zealand flora. Perspectives in Plant Ecology, Evolution and Systematics 11(4): 285-309.
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Callitriche muelleri Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/callitriche-muelleri/ (Date website was queried)