Oreobolus impar
Common name
comb sedge
Synonyms
None
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.
OREIMP
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
Distribution
Endemic. North, South and Stewart Islands. 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 and Stewart Islands. A species favouring permanently damp mineral soils within the ecotone of grassland and bog or shrubland and bog.
Features
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, more or less equal, keel stiff and green, sides pale and membranous, often tinged with red. Hypogynous scales slightly > or = 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 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.
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.
Etymology
oreobolus: Mountain clump
impar: Dissimilar (upper and lower leaf surface)comb-like
Where To Buy
Not commercially available
Attribution
Description adapted from Moore and Edgar (1970).
References and further reading
Moore, L.B.; Edgar, E. 1970: Flora of New Zealand. Vol. II. Government Printer, Wellington.