Species
Corybas orbiculatus
Etymology
Corybas: helmet flower
Common Name(s)
Spider Orchid
Current Conservation Status
2012 - Not Threatened
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 - Not Threatened
2004 - Not Threatened
Authority
Corybas orbiculatus (Colenso) L.B.Moore
Family
Orchidaceae
Flora Category
Vascular - Native
NEMORB
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
Orchids
Synonyms
Corysanthes orbiculata Colenso,; Nematoceras orbiculatum (Colenso) Molloy, D.L.Jones et M.A.Clem.
Distribution
Endemic. North, South, Stewart and Chatham Islands.
Habitat
Coastal to montane (up to 1000 m a.s.l.). Favouring well-lighted, permanently damp sites such as coastal turf, banks and cliff faces. Favouring base-rich substrates such as calcareous mudstones, siltstones, limestones, marble, basalt and basaltic-andesite and recent soils derived from these.
Features
Mainly solitary, terrestrial, tuberous, glabrous, winter to spring-green herb. Tuberoids globose to ellipsoid on extended roots. Plant at flowering 30-35 mm tall, erect. Leaf solitary, fleshy, more or less subcoriaceous, usually spreading and held flat to the ground surface; shortly petiolate, petiole 2.5-6.0 x 1.5-2.0 mm; lamina 15-25 mm long, generally elliptic-cordate, sometimes somewhat broadly cordate, rarely pandurate, apex rounded and shortly apiculate; midrib grooved above, ridged beneath; leaf colour dull dark green to yellow-green above often with purple flecks on margins, or overall, silvery pellucid beneath. Flower solitary, large for plant 15-20(-25) mm long, dark red-green to reddish-purple; peduncle almost sessile, very short and stout, 1.5-2.0 mm long. Ovary 2.5-5.0 mm long, narrowly oblong to ellipsoid, green, yellow-green, or cream, erect or slightly curving back from leaf; subtended by two unequal floral bracts, the smaller forward projecting toward leaf, 1.5-3.0 mm long, linear-subulate, pale green to cream, terete, the larger equal to or exceeding the ovary, 2.5-6.8 mm long, lanceolate to linear-lanceolate, curved, deeply keeled and closely sheathing ovary for about half of length, apex acute, long, drawn out deeply keeled, green, usually with purple or reddish striae or flecks. Dorsal sepal membranous, more or less equal to labellum length 15-20 mm long, greenish-purple or purple red striate, or more or less translucent flecked or streaked with purple, lanceolate-acuminate, apex acute, usually recurved away from labellum; lateral sepals and petals 10-15(-18) mm long, filiform equal to or shorter than dorsal sepal; green, greenish-yellow flecked or striped with purple or maroon, horizontal to suberect or erect, lateral sepals projecting forwards more or less closely embracing labellum; petals projecting forwards and more or less downwards, often touching the leaf. Labellum conspicuous, dark purple-red, maroon to red; labellum tube 3-8 mm long, erect at first then abruptly deflexed 110-130 degrees, and expanding into the lamina; lamina (10-)15-20(-25) x 4-10 mm, narrowly orbicular when flattened, upper margins sharply folded inwards, upper third more or less overlapping; lower surface spreading, apex usually touching leaf at about one-half of leaf length from petiole; margins initially more or less smooth, becoming finely denticulate and then distinctly and broadly deltoid toothed 2-4 times on either side or crenate-denticulate, and with a short median down-curved apiculus.
Similar Taxa
Close to Corybas rivularis and other entities within that species complex. From these it consistently differs by the sepals and petals which are shorter than the labellum. The labellum had distinctly inrolled finely to coarsely toothed margins, and when viewed from the front is distinctly narrowly pointed.
Flowering
August - November
Flower Colours
Green,Red / Pink
Fruiting
October - January
Propagation Technique
Difficult - should not be removed from the wild.
Threats
Not Threatened
Chromosome No.
2n = 36
Endemic Taxon
Yes
Endemic Genus
No
Endemic Family
No
Where To Buy
Not commercially available
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.
Based on rDNA ITS sequence data there is some evidence that suggests that Chatham Island plants referred to this species may be distinct. This requires further research.
Recently Lehnebach (2016) has 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.
Attribution
Fact Sheet prepared for NZPCN by P.J. de Lange 14 April 2007. Description based on herbarium material and Colenso (1891).
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.
Colenso, W. 1890 [1891]: A Description of some Newly-discovered Indigenous Plants, being a Further Contribution towards the making known the Botany of New Zealand. Transactions and Proceedings of the Royal Society of New Zealand 23: 381-391.
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, 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.
This page last updated on 16 Jan 2016