Sonchus grandifolius


Sonchus: sow thistle

Common Name(s)

Chatham Island sow thistle, Embergeria

Current Conservation Status

2012 - At Risk - Recovering

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 - At Risk - Recovering
2004 - Threatened - Nationally Endangered


2012 - CD, EF, IE, RR
2009 - CD, EF, IE, RR


Sonchus grandifolius Kirk



Flora Category

Vascular - Native

Structural Class

Dicotyledonous Herbs - Composites


Embergeria grandifolia (Kirk) Boulos


Endemic to the Chatham Islands. Found on the main islands and some islets.


Sand dunes (usually the foredunes), also coastal cliff ledges, clay promontories and talus slopes.


Thistle-like herb with stout rhizomes and pale green fleshy leaves up to 1 m long, irregularly divided into toothed lobes. It has a milky sap. Erect flower heads with florets that are light purple to pale yellow. Plant dies down in winter. The plant flowers from December to February and fruits in late summer to autumn.

Similar Taxa



December - February

Flower Colours

Violet / Purple,Yellow


Late summer and autumn.

Propagation Technique

Easy from fresh seed. Does best in a free draining, fertile but damp soil in full sun. Dislikes humidity. Plants are often prone to dying in hot weather.


Domestic stock and other browsing animals (including pigs, possums and rodents) are still a threat on Chatham and Pitt Islands. Competition from invasive exotic plants, coastal development and coastal erosion is also a problem in some areas. However, this species has made a spectacular recovery over large parts of its range, and is actively colonising new areas of beach and coastal cliff. It now occurs in numerous secure sites across the Chatham Island group.

Chromosome No.

2n = 36

Endemic Taxon


Endemic Genus


Endemic Family


Life Cycle and Dispersal

Pappate cypselae are dispersed by wind (Thorsen et al., 2009).

Where To Buy

Occasionally available from specialist native plant nurseries.

Taxonomic notes

Recently Garnock-Jones (2014) advocated that Embergeria should be treated as a synonym of Sonchus. Although this decision differs from the conclusion reached by Heenan et al. (2010) NZPCN has elected to follow this decision.


Fact Sheet prepared for NZPCN by P.J. de Lange 1 August 2003.

References and further reading

Garnock-Jones PJ. 2014: Evidence-based review of the taxonomic status of New Zealand's endemic seed plant genera, New Zealand Journal of Botany, DOI: 10.1080/0028825X.2014.902854

Heenan, P.B.; Mitchell, A.D.; de Lange, P.J.; Keeling, J.; Paterson, A.M. 2010: Late Cenozoic origin and diversification of Chatham Islands endemic plant species revealed by analyses of DNA sequence data. New Zealand Journal of Botany 48: 83–136.

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: 285-309

Walls, G.; Baird, A.; de Lange, P.J.; Sawyer, J.W.D. 2002: Threatened plants of the Chatham Islands. Wellington, Department of Conservation.

This page last updated on 20 Jan 2015