Species

Mazus arenarius

Etymology

Mazus: tear (after protuberance on throat of flower)
arenarius: sand dweller

Current Conservation Status

2018 - At Risk - Declining

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

2012 - At Risk - Naturally Uncommon
2009 - At Risk - Naturally Uncommon
2004 - Gradual Decline

Qualifiers

2012 - DP, RR

Authority

Mazus arenarius Heenan, P.N.Johnson et C.Webb

Family

Mazaceae

Flora Category

Vascular - Native

NVS Species Code

MAZARE

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.

Structural Class

Dicotyledonous Herbs other than Composites

Synonyms

None

Distribution

Endemic to coastal Otago, Southland and Stewart Island.

Habitat

In dune fields where it grows in seasonally damp swales (depressions), or on rocky coastal lines within coastal turf developed around seepages. Occasionally found along the margins of slow flowing tidal streams.

Features

Mat-forming, creeping, rhizomatous herb forming dense green-brown or purple brown patches. Leaves 10-30(-120) mm, opposite, spathulate, obovate to broad-elliptic purple-brown when exposed, green-brown in shade, upper surface finely hairy. Inflorescences terminal, 2-3(-4) flowered. Corolla 6.5-9 mm long, white, flushed purple in throat, palate yellow. Lower corolla lobes 3, these rounded, sometimes square or rectangular, or slightly narrowed toward proximal end, apex often retuse. Upper lobes 2, narrow-triangular, apex subacute, sometimes retuse. Fruit (3.5-)4.5-7(-9) x (3.5-)4-5(-6) mm, red-purple. Seed 0.7-0.9 mm.

Similar Taxa

Perhaps closest to M. radicans from which it differs by the smaller, unmottled leaves, smaller, white, scarcely flushed purple, flowers with the lower corolla lobes rounded, and usually with square or retuse apices, while the upper corolla lobes are subacute. As far as is known neither species occur sympatrically.

Flowering

November - December

Flower Colours

Violet / Purple,White

Fruiting

December - July (-December)

Propagation Technique

Easy from the division of whole plants and seed but not especially attractive, hard to maintain and unless conditions are right slow growing.

Threats

Threatened by the small, fragmented population sizes, the dynamic nature of the species habitat coupled with land development and competition from naturalised plants. Not a common species known only from 7 sites in the southern South Island and 7 on Stewart Island. Several of these populations are on private land and some populations are very small and are known to be experiencing a slow rate of decline.

Chromosome No.

2n = 104

Endemic Taxon

Yes

Endemic Genus

No

Endemic Family

No

Where To Buy

Not commercially available.

 

Attribution

Fact sheet prepared for NZPCN by P.J. de Lange 1 October 2003. Description adapted from Heenan et al. (1996).

References and further reading

Heenan, P.B.; Webb, C. J.; Johnson, P. N. 1996: Mazus arenarius (Scrophulariaceae), a new, small-flowered, and rare species segregated from M. radicans. New Zealand Journal of Botany 34(1): 33-40.

This page last updated on 16 Apr 2014