Oreobolus impar
Common names
comb sedge
Biostatus
Native – Endemic taxon
Category
Vascular
Structural class
Sedges
Detailed description
Perennial sedge forming a compact whitish-green or yellowish-green mat 20–50 mm high. Stems densely packed. Leaves spreading, not obviously distichously; lamina 0.5–1.0 mm wide, channelled at the base, abruptly widening to the upper flat portion, abaxial surface rich in stomata with only the median nerve prominent, adaxial surface having no stomata except occasionally with a few present toward the apices or very near the margin, with two lateral nerves prominent and the median nerve occasionally extending towards the apex; sheath about twice the width of lamina, 5–7-nerved, without conspicuous auricles. Mature peduncle leaves bearing 1–3 spikelets. Glumes 3, ± =, keel stiff and green, sides pale and membranous, often tinged with red. Hypogynous scales slightly ≥ nut, very narrow-linear, white or pale brown. Stamens (2)–3. Nut slightly > 1 mm long, c. 1 mm diameter, almost flat at the apex with a large depression, obovoid, shortly but distinctly stipitate, light grey.
Similar taxa
Closest to O. strictus Bergg. from which it differs by the densely packed stems; leaves with stomata only on the undersides, and by the hypogynous scales > or occasionally equal in length to the nut. From O. pectinatus Hook.f. it differs by its compact mat-forming rather than cushion-forming growth habit, leaves usually not distichously arranged with only the median nerve visible on the leaf undersides at the widest part of the lamina; and by the usually red-tinged glumes.
Distribution
Endemic. North Island, South Island and Stewart Island/Rakiura. Confined to the Central Volcanic Plateau and adajcent main axial ranges in the North Island.
Habitat
Coastal to alpine (up to 1500 m a.s.l.). Mostly alpine descending to sea level only in the southern South Island and Stewart Island/Rakiura. A species favouring permanently damp mineral soils within the ecotone of grassland and bog or shrubland and bog.
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 | Not Threatened
Detailed taxonomy
Family
Synonyms
None
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Ecology
Flowering
October–December
Fruiting
November–April
Propagation technique
Easily grown from rooted pieces and probably from fresh seed. However, this species is best grown in a cooler climate or kept in a pot within an alpine house. it is very slow growing.
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]
OBL: Obligate Wetland
Almost always is a hydrophyte, rarely in uplands (non-wetlands).
Other information
Where To Buy
Not commercially available
Etymology
oreobolus: Mountain clump
impar: Dissimilar (upper and lower leaf surface)comb-like
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.
OREIMP
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 | Not Threatened
2012 | Not Threatened
2009 | Not Threatened
2004 | Not Threatened
Regional conservation statuses
The regional threat classification system leverages off the national assessments in the NZTCS, providing information relevant for the regional context. Otago conservation status information is sourced from the “Regional conservation status of indigenous vascular plants in Otago” Jarvie S et al. (2024) report.
Otago: 2024 | Regionally Not Threatened
Referencing and citations
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.
Attribution
Description adapted from Moore and Edgar (1970).
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.