Corysanthes oblonga (Hook.f.) Hook.f., Nematoceras oblongum Hook.f. Singularybas oblongus (Hook.f.) Molloy, 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 = c.34, 34
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 | Not Threatened
Previous conservation statuses
2009 | Not Threatened
2004 | Not Threatened
Endemic. North, South, Stewart, Chatham, Auckland and Campbell Islands
Coastal to subalpine (up to 1200 m a.s.l.). Widespread on consolidated sand within shrubland and sand dune forests, in shrubland, tall forest, lowland peat bogs and subalpine mires and in cloud forest. Often found on mossy banks within dense forest, or on the margins of slow flowing forest streams.
Terrestrial, tuberous, winter-spring flowering, glabrous perennial herb. Plant at flowering 20-30 mm tall, usually much taller in fruit. Stem erect, purple-red, maroon or pale whitish. Leaf usually solitary, rarely paired, sessile, rather membranous, 10-40 mm long, upper surface dark green, green with red flecks, or green with red veins, undersides silvery-red or silvery-white, ovate-oblong, apex apiculate, base cordate or rounded, margins undulose or plane, entire. Floral bract prominent, foliaceous, equal in length to ovary, broadly ovate to elliptic, hyaline, pale green or pale yellow, usually flecked with red, purple or maroon. Flowers 1(-2). Dorsal sepal slightly longer than labellum, somewhat fleshy, broadly spathulate, apex broadly obtuse to apiculate, hyaline, whitish flecked with purple or red to greenish-white (rarely completely white) with red flecks; lateral sepals white to slightly off-white or completely beetroot purple, hyaline, very long, filiform. Petals similar to lateral sepals but slightly shorter. Labellum horizontal, or slightly tilted upwards, 5-10 mm long, dark crimson, to crimson-purple (almost black) or rarely completely white, base auriculate, otherwise curved to form a cylinder with a wide flaring, fimbriate mouth (fringed with numerous coarse hyaline teeth); internally with numerous retrorse hair like cilia present from near the mid-line back. Fruit a broadly cylindrical to ovoid-ellipsoid capsule, borne on a peduncle which usually elongates greatly at fruiting
None when flowering. The dark crimson coloured frimbriate labellum (with its conspicuous fringe of hyaline teeth) is extremely distinctive. Only Molloybas cryptanthus has a similar fimbriate flower but that saprophytic species lacks leaves (and chlorophyll), is rhizomatous, and its flowers are usually hyaline with purple or red flecks or more rarely completely colourless. The sessile usually dark green red flecked or red veined leaves with their usually undulose margins are also rather diagnostic.
September - February
November - April
Difficult - should not be moved from the wild
corybas: Helmet flower
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.
In addition some late-flowering forms growing on sand in the far north, a widespread white-flowered race and, diminutive plants found on the Chatham Islands require further investigation. In the Waikato this species often grows in a heavily reduced state on restiad peat. Plants cultivated from peat bogs retain their small size and seem comparable to Chatham Island plants.
Fact Sheet prepared for NZPCN 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.
Moore, L.B.; Edgar, E. 1970: Flora of New Zealand. Vol. II. Government Printer, Wellington.
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Corybas oblongus Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/corybas-oblongus/ (Date website was queried)