Callitriche petriei subsp. petriei


Callitriche: From the Greek kalli 'beautiful' and thrix 'hair', referring to the beautiful stems
petriei: Named after Donald Petrei (1846 -1925), Otago botanist

Common Name(s)

Petrie's starwort

Current Conservation Status

2012 - Not Threatened

Conservation status of New Zealand indigenous vascular plants, 2012
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2012 using the New Zealand Threat Classification System (NZTCS). This report includes a statistical summary and brief notes on changes since 2009 and replaces all previous NZTCS lists for vascular plants. Authors: Peter J. de Lange, Jeremy R. Rolfe, Paul D. Champion, Shannel P. Courtney, Peter B. Heenan, John W. Barkla, Ewen K. Cameron, David A. Norton and Rodney A. Hitchmough. File size: 792KB

Previous Conservation Status

2009 - Not Threatened
2004 - Not Threatened


Callitriche petriei R.Mason subsp. petriei



Flora Category

Vascular - Native

Structural Class

Dicotyledonous Herbs other than Composites




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.

Similar Taxa

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

Propagation Technique

Easily grown from rooted pieces and fresh seed, A delicate plant that is unlikely to be widely cultivated.


Not Threatened

Chromosome No.

2n = 20

Endemic Taxon


Endemic Genus


Endemic Family


Life Cycle and Dispersal

Mericarps possibly by water and attachment (Thorsen et al., 2009).

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

This page last updated on 23 Sep 2014