Corybas dienemus
Biostatus
Native – Endemic taxon
Current conservation status
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2022-2023 using the New Zealand Threat Classification System (NZTCS) – more information about this can be found on the NZTCS website. This report includes replaces all previous NZTCS lists for vascular plants. Previous assessments can be found here.
- Conservation status of vascular plants in Aotearoa New Zealand, 2023. 2024. Peter J. de Lange, Jane Gosden, Shannel P. Courtney, Alexander J. Fergus, John W. Barkla, Sarah M. Beadel, Paul D. Champion, Rowan Hindmarsh-Walls, Troy Makan and Pascale Michel Department of Conservation. Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2023 | Threatened – Nationally Critical | Qualifiers: DPR, DPS, DPT, SO
Category
Vascular
Structural class
Orchids
Flower colours
Green, Red/Pink
Detailed description
Terrestrial orchid up to 50 mm tall at flowering, occurring as solitary plants or forming small colonies. Leaf solitary, 15–25 mm diameter, orbicular, dark green above, paler beneath, pellucid, cupular and semi-erect at flowering, apex apiculate, lamina firmly fleshy to almost succulent. Flower solitary, pale green and red-purple, semi-erect, positioned within cordate base of leaf. Dorsal sepal linear-oblanceolate, acuminate, cucullate (hooded) over labellum tube; lateral sepals and petals filiform, long-acuminate, subequal, stiffly erect. Labellum tubular at base, strong V-shaped in transverse; lateral margins flared to incurved, distinctly irregularly crenate.
Similar taxa
This species had been confused with C. macranthus from which it is allopatric. The distinctive cupular leaves, and pale-green and red, semi-erect flowers held within the cordate leaf bases immediately distinguish it from all other Corybas species.
Distribution
Endemic. New Zealand: North Island and probably southern South Island, Macquarie Island. Very similar looking plants have also been collected from Campbell Island/Motu Ihupuku.
Threats
Unknown. The largest population knwon so far occurs on Macquarie Island where it is believed to be secure but following its recent (2013) recognition from the southern North Island this species may be better treated as ‘Data Deficient’ until its full extent in New Zealand is determined. The sole confirmed New Zealand population is on a track side and so vulnerable to tracking maintenance and plant collectors.
Detailed taxonomy
Genus
Family
Synonyms
Corysanthes dienema (D.L.Jones) Szlach.; Nematoceras dienemum (D.L.Jones) D.L.Jones, M.A.Clem. et Molloy
Taxonomic notes
Considerable research is underway to investigate the validity of the segregate genera split from Corybas R.Br. by Jones et al. (2002). Whilst much of that work has yet to be published, on advice from Australian Orchidologists Peter Weston and Stephen Hopper (pers. comm., July 2011, November 2014), all of the segregate genera recognised for New Zealand by Jones et al. (2002) are returned to Corybas (see also Lyon 2014).
Lehnebach (2016) made three combinations for those Nematoceras lacking valid names in Corybas. This action now enables the full transfer of Nematoceras back to Corybas. However, as of writing, a formal publication rejecting the segregation of Corybas by Jones et al. (2002) has yet to be published. Lehnebach cites an unpublished PhD (Lyon 2014) that indicates this move is imminent.
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Ecology
Flowering
November–Janaury
Fruiting
December–April
Propagation technique
Difficult—should not be removed from the wild. Can be grown in basic orchid mix consists of 2 parts medium coarse sand, ideally clean river sand; 2 parts soil, humus or leaf-mould; 1 part weathered sawdust or rotting wood; 1 part granulated bark. Many Corybas thrive better if more leaf-mould is added, and the plants grown in 50–70% shade, in the cooler, darker end of the shade-house, in pots kept moist throughout the growing period.
Other information
Etymology
corybas: Helmet flower
Manaaki Whenua Online Interactive Key
Previous conservation statuses
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2022-2023 using the New Zealand Threat Classification System (NZTCS) – more information about this can be found on the NZTCS website. This report includes replaces all previous NZTCS lists for vascular plants. Previous assessments can be found here.
- Conservation status of vascular plants in Aotearoa New Zealand, 2023. 2024. Peter J. de Lange, Jane Gosden, Shannel P. Courtney, Alexander J. Fergus, John W. Barkla, Sarah M. Beadel, Paul D. Champion, Rowan Hindmarsh-Walls, Troy Makan and Pascale Michel Department of Conservation. Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2017 | Threatened – Nationally Critical | Qualifiers: DP, TO
2012 | Data Deficient | Qualifiers: SO
2009 | At Risk – Naturally Uncommon | Qualifiers: RR
2004 | Range Restricted
Referencing and citations
References and further reading
Jones DL. 1993. Flora of Australia 50: 572. https://www.dcceew.gov.au/sites/default/files/env/pages/ea399fe6-5ae3-465d-8613-1c10e68a075f/files/flora-australia-50-oceanic-islands-2.pdf
Jones DL, Clements MA, Sharma IK, Mackenzie AM, Molloy BPJ. 2002. Nomenclatural notes arising from studies into the Tribe Diurideae (Orchidaceae). The Orchadian 13(10): 437–468. https://www.biodiversitylibrary.org/item/310769#page/5/mode/1up.
Lehnebach C. 2016. New combinations and a replacement name for three New Zealand spider orchids (Corybas). The New Zealand Native Orchid Journal 139. 4–5.
Lyon SP. 2014. Molecular systematics, biogeography, and mycorrhizal associations in the Acianthinae (Orchidaceae), with a focus on the genus Corybas. PhD Thesis, University of Wisconsin-Madison, USA. https://asset.library.wisc.edu/1711.dl/UAXO3VHO6P7EH8Y/R/file-19145.pdf.
Attribution
Fact Sheet prepared for NZPCN by P.J. de Lange (14 April 2007). Description modified from Jones (1993).