Swamp helmet orchid
Corysanthes carsei Cheeseman; Corybas matthewsii (Cheeseman) Schltr.; Corysanthes matthewsii Cheesem.; Anzybas carsei (Cheeseman) D.L.Jones et M.A.Clem.
Vascular – Native
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.
2n = 36
Current conservation status
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2017 using the New Zealand Threat Classification System (NZTCS). This report includes a statistical summary and brief notes on changes since 2012 and replaces all previous NZTCS lists for vascular plants. Authors: By Peter J. de Lange, Jeremy R. Rolfe, John W. Barkla, Shannel P. Courtney, Paul D. Champion, Leon R. Perrie, Sarah M. Beadel, Kerry A. Ford, Ilse Breitwieser, Ines Schönberger, Rowan Hindmarsh-Walls, Peter B. Heenan and Kate Ladley.
2012 | Threatened – Nationally Critical | Qualifiers: CD, EF, OL, RR
Previous conservation statuses
2009 | Threatened – Nationally Critical | Qualifiers: CD, RF, EF, OL
2004 | Threatened – Nationally Critical
Possibly endemic (see Notes on taxonomy, below). North Island, from near Kaitaia south to Moanatuatua. Now only known in New Zealand from the Te Reao Arm of the Whangamarino Wetlands near Te Kauwhata, in the Huntly Basin, northern Waikato. Present in Australia, within New South Wales and Victoria, where it is now regarded as very uncommon.
Known only from one site where it grows in open Schoenus/ Empodisma sedge/wirerush vegetation, though it was formerly more common in several, now drained, Sporadanthus-dominated bogs.
Terrestrial orchid of restiad-dominated peat bogs. Plant 10-30 mm tall at flowering. Stem erect. Leaf 1(-2), 10-25(-30) mm long, green, sessile, ovate. Floral bract 1. Flower solitary, conspicuous, raised well above leaf. Perianth 8-10(15) mm long, horizontal. Dorsal sepal spathulate from narrow arching claw, obtuse, hooded, slightly shorter than labellum, apex deeply cleft; base to mid section dark maroon-red, fading to yellow-green at apex, faintly striped maroon 2-6 times. Lateral sepals and petals linear 4-5(-8) mm long, white, more or less appressed to labellum. Labellum tubular, margins overlapping, entire, apex usually extending well beyond dorsal sepal; basal portion dark maroon-red, otherwise white, maroon colour extending as 8(-10) stripes, these almost reaching apex. Internal portion of labellum covered in prominent, retrorse, hair-like calli, forming a distinct band near labellum mouth, extending along mid-line and nerves for about half labellum length.
Corybas rotundifolius, is similar but larger. The dorsal sepal lacks the cleft tip seen in C. carsei. The labellum is as long or slightly longer than the dorsal sepal, while the internal hairlike inward facing labellar calli are more prominent and extend nearly towards the column. Corybas rotundifolius flowers in mid-winter, and is more usually found in forested habits and on the margins of gumland scrub, only rarely does it grow within peat bogs.
Difficult. Should not be removed from the wild
Wetland drainage and plant collectors have contributed to the decline of this species in the past. The single remaining population is now mainly at risk through natural succession.
corybas: Helmet flower
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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)
In addition the taxonomic status of Corybas carsei and the Australian C. fordhamii needs resolution. Morphologically there seems little to distinguish them. For now Corybas carsei is accepted as ‘possibly’ endemic. If these two species prove conspecific then C. carsei as the older name has priority.
Fact Sheet by P.J. de Lange (1 January 2005). Description adapted from Moore and Edgar (1970)
References and further reading
Jones, D.L.; Clements, M.A.; Sharma, I.K.; Mackenzie, A.M.; Molloy, B.P.J. 2002: Nomenclatural notes arising from studies into the Tribe Diurideae (Orchidaceae). The Orchadian 13: 437-468.
Lyon, S. P. 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.
Moore, L.B.; Edgar, E. 1970: Flora of New Zealand. Vol. II. Government Printer, Wellington.
Please cite as: de Lange, P.J. (Year at time of access): Corybas carsei Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/corybas-carsei/ (Date website was queried)