Carex kermadecensis
Common name
Kermadec sedge
Synonyms
Carex forsteri Wahl. subsp. insularis W.R.B.Oliver
Family
Cyperaceae
Flora category
Vascular – Native
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Structural class
Sedges
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.
CARKER
Chromosome number
2n = c.60
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) – more information about this can be found on the NZTCS website. This report includes a statistical summary and brief notes on changes since 2012 and replaces all previous NZTCS lists for vascular plants.
Please note, threat classifications are often suggested by authors when publications fall between NZTCS assessment periods – an interim threat classification status has not been assessed by the NZTCS panel.
- Conservation status of New Zealand indigenous vascular plants, 2017 . 2018. 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. 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: CD, IE
Previous conservation statuses
2012 | At Risk – Naturally Uncommon | Qualifiers: CD, IE
2009 | At Risk – Naturally Uncommon | Qualifiers: IE
2004 | Range Restricted
Distribution
Endemic. Kermadec Islands group where it is known only from Raoul and Macauley Islands.
Habitat
Coastal forest where it is usually found amongst boulders, rubble and near sea bird nesting sites. Sometimes found in open exposed places but generally prefers shaded situations.
Detailed description
Rather robust tufted, light yellow-green to green tussock forming sedge usually of shaded forested slopes. Culms up to 450 mm tall, 2 mm diameter, triquetrous, finely and faintly scabrid just below inflorescence; basal sheaths light brown. Leaves much > culms, 7–10 mm wide, double-folded, margins scabrid. Inflorescence of 5–10 usually compound spikes. Spikes 20–55 × 5–7 mm, approximate or with the lower 2–4 more distant, erect on stiff peduncles; the terminal spike wholly or mostly male, or completely female; remaining spikes female with occasional male flowers at the base; lower subtending bracts leaf-like, much > inflorescence. Glumes (excluding awn) < utricles, ovate-oblong, emarginated or acute, margins fimbriate towards apex, light brown or with minute dark brown flecks, chartaceous to membranous, awns up to 3 mm long, pale green to straw-coloured, scabrid,. Utricles 3–4 × 1.5 mm, trigonous, ellipsoid or more or less ovoid, nerves distinct, membranous, grey-brown with red-brown flecks, beck 1–2 mm long, deeply and acutely bifid, orifice and margins of beak and of upper part of utricles usually scabrid. Stigmas 3. Nut 2 mm long, dark brown, trigonous, oblong-obovoid.
Similar taxa
As the only carex on the Kermadecs field identification is not usually a problem. However, herbarium material could be confused with C. elingamita Hamlin of the Three Kings Islands group. From that species C. kermadecensis differs consistently by the lowermost spikes predominantly female rather than largely male toward the top, by the utricles 3–4 mm rather than 4–4.5 mm long and by the nut coloured dark brown rather than red brown. That they are closely allied is inferred from nrDNA ITS sequences which position both species as sister taxa.
Flowering
October–January
Fruiting
October–May
Life cycle
Nuts surrounded by inflated utricles are dispersed by granivory and wind (Thorsen et al., 2009).
Propagation technique
Easily grown in a warm sheltered site, prefers semi-shade. Very cold sensitive.
Threats
A naturally uncommon , range restricted species. However, it has not been seen on Macauley Island since 1989.
Etymology
carex: Latin name for a species of sedge, now applied to the whole group.
kermadecensis: From the Kermadec Islands
Attribution
Description adapted from Moore and Edgar (1970)
References and further reading
Moore LB, Edgar E. 1970. Flora of New Zealand, Volume II. Indigenous Tracheophyta: Monocotyledones except Gramineae. Government Printer, Wellington, NZ. 354 p.
Thorsen MJ, Dickinson KJM, Seddon PJ. 2009. Seed dispersal systems in the New Zealand flora. Perspectives in Plant Ecology, Evolution and Systematics 11: 285–309.