Species
Tetrachondra hamiltonii
Etymology
hamiltonii: Named after W. S. Hamilton (of Southland)
Current Conservation Status
2018 - Threatened - Nationally Vulnerable
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 - Data Deficient
2009 - At Risk - Declining
2004 - Serious Decline
Qualifiers
2012 - Sp
2009 - DP, Sp
Authority
Tetrachondra hamiltonii Petrie ex Oliv.
Family
Tetrachondraceae
Flora Category
Vascular - Native
TETHAM
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
Tillaea hamiltonii Kirk nom. nud.
Distribution
Endemic to New Zealand. In the North Island only known from the N.W. Ruahine corner. In the South Island localised but widespread, with its main centre of distribution Otago, western Southland, Fiordland and Stewart Island.
Habitat
A species of open, compact turf communities such as those developed along lake and tarn margins, flushes and seepages. Occasionally found in suitably open sites within forest.
Features
Creeping perennial herb rooting at nodes forming diffuse to dense turf-like patches. Stems fleshy, distinctly angled, square in cross-section, dark striped. Leaves opposite, 2 x 2 mm, broadly ovate to obovate-oblong, bright green or mottled with red, fleshy, sparsely covered with indistinct circular oil glands, glabrescent (leaf margins often faintly ciliolate), shortly petiolate to sessile, bases decurrent with stem. Flowers soliatry, off-white to greenish-white. Calyx-lobes minute, ovate-triangular, corolla lobes 4, obovate-oblong, pubescent. Stamens and styles 4. Fruit of 4 brown setulose nutlets. These broadly elliptic or obovate, (1-)1.1-1.4(-1.5) mm.
Similar Taxa
Without fruits this diminutive creeping herb could be easily confused with a diverse range of other unrelated turf-forming herbs, e.g., Nertera spp., Crassula spp., Galium spp. However, the distinctive 4-fruited setulose nutlets immediately distinguish it from these and other potential look alikes.
Flowering
Flowers may be found throughout the year
Flower Colours
Green,White
Fruiting
Fruits may be found throughout the year
Propagation Technique
Easily grown from the division of whole plants.
Threats
A naturally uncommon species of open damp turf, seepages, and the marginal turf communities of lakes and tarns. Sometimes in open scrub or damp grassland. Indications are that in parts of its range it is declining possibly as a consequence of taller, faster growing weeds spreading into the habitats it requires.
Chromosome No.
2n = 72
Endemic Taxon
Yes
Endemic Genus
No
Endemic Family
No
Where To Buy
Not commercially available but plants are held by several Botanic Gardens and specialist growers. It is very easily grown but is not particularly attractive.
Attribution
Fact Sheet prepared for NZPCN by P.J. de Lange 1 August 2003. Description based on Allan (1961).
References and further reading
Allan, H.H. 1961: Flora of New Zealand. Vol. I. Wellington, Government Printer
This page last updated on 13 May 2014