Carex perplexa
Common names
Surville Cliffs bastard grass
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 | At Risk – Naturally Uncommon | Qualifiers: OL
Category
Vascular
Structural class
Sedges
Detailed description
Tufted sedge of ultramafic habitats forming large, spreading clumps. Culms 400–500 × 0.7–0.9 mm, glabrous, trigonous, > leaves; leaf-sheaths 30 mm or less, yellow-brown, nerves light brown. Leaves 6–11 per culm, 200–550 × 2–5 mm, weakly channelled, green; upper surface keeled, keel scabrid, margin scabrid, apex acute, trigonous, scabrid. Spikes linear, up to 55 mm long, 2–3 mm wide, usually subtended by 1 leaf-like bract 15–95 × 0.2–1.2 mm; female florets proximal, 15–24, internodes 3.5 mm long at spike base decreasing to 0.6 mm above; male florets distal, 15–20, overlapping. Glumes: male glumes 3.5–4 × 1 mm, narrow elliptic-lanceolate, light brown; female glumes 3.5–4 × 1–1.2 mm, elliptic lanceolate to narrow elliptic, deciduous, light brown. Utricles 4.2–4.3 × 1.2–1.3 mm, planoconvex, ovate to elliptic, glabrous, light brown. Nuts 2.2–2.4 × 1–1.2 mm, oblong, light green to silver-green.
Similar taxa
Carex perplexa appears to be most closely related to C. uncinata L.f.. This is a larger plant with longer spikes (up to 200 mm long), more female flowers per spike (60–120), and with larger fruits (utricles) and glumes. Carex uncinata, in common with all other New Zealand hook sedges except C. subtilis K.A.Ford and C. parvispica K.A.Ford (which have 2n = 94, 96 chromosomes respectively), has 2n = 88 chromosomes.
Distribution
Endemic. North Island, North Cape, Surville Cliffs, where it is only known from one small area of the 120 ha exposure of ultramafic rock.
Habitat
Ultramafic rock and talus in shaded sites under pohutukawa (Metrosideros excelsa Sol. ex Gaertn.) trees. Usually found growing with Carex ophiolithica de Lange et Heenan.
Threats
Currently this species is confined to a single remnant stand of forest on the Surville Cliffs. This forest remnant is a survivor from past fires which all but destroyed the forest of the ultramafic zone at North Cape. Uncinia perplexa dislikes strong sun and so is vulnerable to the loss of the associated pohutukawa forest. The main threat to this forest is continuing browse from possums but fire is also a serious risk. Some weeds such as pampas grass (Cortaderia selloana (Schult. et Schult.f.) Asch. et Graebn.) and prickly hakea (Hakea sericea Schrad. et J.C.Wendl.) also pose a risk through potential competition should they become better established at North Cape.
Detailed taxonomy
Genus
Family
Synonyms
Uncinia perplexa Heenan et de Lange
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Ecology
Flowering
December
Fruiting
January–April
Propagation technique
Very easy from divisions of whole plants and from seed. However plants are slow growing and inclined to die unless fertilised frequently with a magnesium rich fertiliser.
Other information
Cultivation
Not commericially available. However plants are held by one University and by Landcare Research.
Etymology
carex: Latin name for a species of sedge, now applied to the whole group.
perplexa: From the Latin per (completely) and plectare (to entwine), referring to the entangled nature of the relationship among the species
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.
CARPER
Chromosome number
2n = 132
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: OL
2012 | At Risk – Naturally Uncommon | Qualifiers: OL
2009 | Threatened – Nationally Critical | Qualifiers: CD, OL
2004 | Threatened – Nationally Critical
Referencing and citations
References and further reading
Heenan PB, de Lange PJ. 2001. A new, dodecaploid species of Uncinia (Cyperaceae) from ultramafic rocks, Surville Cliffs, Northland, New Zealand. New Zealand Journal of Botany 39(3): 373–380. https://doi.org/10.1080/0028825X.2001.9512743.
Attribution
Fact Sheet prepared for NZPCN by P.J. de Lange 7 March 2004. Description modified from Heenan & de Lange (2001).
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Carex perplexa Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/carex-perplexa/ (Date website was queried)