Corunastylis nuda
Common names
red leek orchid
Biostatus
Native
Category
Vascular
Structural class
Orchids
Flower colours
Green, Red/Pink
Detailed description
An erect, reed/rush-like reddish green orchid up to 500 mm tall of open or sparsely vegetated shrubland. Base of plant clad in persistent, brown, somewhat fibrous sheaths of old scale-leaves; these enclosing current tuber and remnant tubers of past seasons’ growth. Stem 1–3 mm diameter, dark green to red-green to reddish mottled, erect, rushlike, leafless almost up to inflorescence. Leaf very much < than inflorescence length; lamina inconspicuous, narrowly involute, shortly-sheathing. Inflorescence a raceme of 5–25 closely spaced flowers. Perianth dark red or reddish-green, narrow, horizontal, with a distinct knee projecting upwards. Dorsal sepal 2.5–3 mm, deeply concave, broadly ovate with a small apiculus. Lateral sepals definitely longer, very shortly fused (connate) at base, deeply concave, elliptic, tipped with a small spathulate, easily detached gland-like structure. Petals shorter, membranous, hair-tipped. Labellum just shorter than or equal to petals, dark red (rarely reddish-green), articulate by a narrow curved claw to long column-foot; limb broadly oblong, almost auriculate at base; callii 2, longitudinal, more or less parallel, finely and closely papillose; margins distinctly though finely ciliate, cilia usually red or red-green. Lateral processes of column as tall as anther; apices bfid with the anterior lobe more acute and very finely ciliolate. Anthers on a very short filament (almost sessile), overtopping rostellum, apiculate. Stigma about the same height as the column base.
Similar taxa
Superficially similar to Corunastylis pumila (Hook.f.) D.L. Jones et M.A. Clem. from which it differs by its red-green to dark green (rather than yellow-green to green ) stem and leaf; much short leaf, horizontal rather than drooping, scarcely opening, reddish (rather than widely opening almost campanulate yellowish) flowers, and red rather than greenish labellum with finely ciliate margins.
Distribution
Indigenous. New Zealand: North Island (from about Great Barrier Island (Aotea Island) and Albany south), South Island, Chatham Islands. Also Australia.
Habitat
A species of mainly lowland to montane areas (1–900 m a.s.l.) favouring open shrublands including pakihi sites, skeletal soils over lying rock, peat bogs, and infertile clay bank scrub and road banks. It also grows in short grassland including pastures overlying sand, clay or gley podzols that are now dominated by introduced grasses.
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 Vulnerable | Qualifiers: Sp, DPR, DPS, DPT, SO
Threats
Apparently a naturally uncommon, biologically sparse species. However, as with Corunastylis pumila much of the habitat this species favours has been destroyed over the last 100 or so years and it is quite likely that this orchid has undergone a massive range reduction. Nevertheless probably because it has always been more wide-ranging than C. pumila, it remains less threatened by continued development of lowland New Zealand. Despite this it is probably another species whose exact conservation status may require adjustment to take into account past habitat losses and continuing habitat modification. This is especially because much of its habitat remains unprotected and that which is, without periodic disturbance is likely to revert to taller vegetation unsuitable for this and other orchid species.
Detailed taxonomy
Genus
Family
Synonyms
Genoplesium nudum (Hook.f.) D.L.Jones & M.A.Clem.; Prasophyllum nudum Hook.f.
Endemic taxon
No
Endemic genus
No
Endemic family
No
Ecology
Flowering
December–August
Fruiting
January–November
Propagation technique
Difficult—should not be removed from the wild.
Wetland plant indicator status rating
Information derived from the revised national wetland plant list prepared to assist councils in delineating and monitoring wetlands (Clarkson et al., 2021 Manaaki Whenua – Landcare Research Contract Report LC3975 for Hawke’s Bay Regional Council). The national plant list categorises plants by the extent to which they are found in wetlands and not ‘drylands’. The indicator status ratings are OBL (obligate wetland), FACW (facultative wetland), FAC (facultative), FACU (facultative upland), and UPL (obligate upland). If you have suggestions for the Wetland Indicator Status Rating, please contact: [Enable JavaScript to view protected content]
FAC: Facultative
Commonly occurs as either a hydrophyte or non-hydrophyte (non-wetlands).
Other information
Etymology
nuda: Nude or naked
Manaaki Whenua Online Interactive Key
NVS code
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.
CORNUD
Chromosome number
2n = 44
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 | At Risk – Naturally Uncommon | Qualifiers: EF, SO, Sp
2012 | At Risk – Naturally Uncommon | Qualifiers: EF, SO, Sp
2009 | At Risk – Naturally Uncommon | Qualifiers: SO, EF
2004 | Sparse
Regional conservation statuses
Auckland: 2025 | Regionally Data Deficient
The regional threat classification system leverages off the national assessments in the NZTCS, providing information relevant for the regional context. Auckland conservation status information is sourced from the “Conservation status of vascular plant species in Tāmaki Makaurau / Auckland” Simpkins E et al. (2025) report.
Referencing and citations
Attribution
Fact sheet prepared by P.J. de Lange for NZPCN (1 June 2013). Description adapted from: Moore, L.B.; Edgar, E. 1970: Flora of New Zealand. Vol. II. Government Printer, Wellington.
Some of this factsheet information is derived from Flora of New Zealand Online and is used under a Creative Commons Attribution 3.0 New Zealand licence.