Callitriche petriei subsp. petriei
Vascular – Native
Dicotyledonous Herbs other than Composites
2n = 20
Current conservation status
The conservation 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). 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.
2012 | Not Threatened
Previous conservation statuses
2009 | Not Threatened
2004 | Not Threatened
Endemic. North and South Islands. Scarce north of Auckland.
Coastal to alpine in damp muddy ground, lake, pond and tarn turf, in damp temporary pools, puddles and soaks within forest and scrub. Sometimes found permanently submerged.
Diminutive, dioecious to subdioecious, widely creeping perennial with weakly ascending to erect branches 30-100 mm long. Leaves 1.1-5 mm long, bright green to yellow green, spathulate to orbicular, the larger leaves often with short side veins arising from the midrib, and with two lateral veins. Flowers solitary, alternate on either side of stem, ebracteate. Fruit an more or less elliptic mericarp, laterally compressed, 0.6-0.7 x 0.7-0.9 mm, dull grey-brown or orange-yellow, lobes not rounded, keeled or winged.
Differs from C. petriei subsp. chathamensis by its dioeciousrather than monoecious habit, smaller leaves (1.1-5 cf 2.5-8 mm), smaller fruit ( 0.6-0.7 x 0.7-0.9 cf. 0.6-0.9 x 0.7-1.1 mm), and restriction to the North and South Islands of New Zealand.
November - January
January - February
Mericarps possibly by water and attachment (Thorsen et al., 2009).
Easily grown from rooted pieces and fresh seed, A delicate plant that is unlikely to be widely cultivated.
callitriche: From the Greek kalli ‘beautiful’ and thrix ‘hair’, referring to the beautiful stems
petriei: Named after Donald Petrei (1846 -1925), Otago botanist
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 2009 Vol. 11 No. 4 pp. 285-309
Please cite as: de Lange, P.J. (Year at time of access): Callitriche petriei subsp. petriei Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/callitriche-petriei-subsp-petriei/ (Date website was queried)