Carex astonii
Common name
Aston’s sedge
Synonyms
Carex druceana var. astonii (Hamlin) Edgar
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.
CRXAST
Chromosome number
2n = c.60
Current conservation status
The threat classification 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. 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. Please note, threat classifications are often suggested by authors when publications fall between NZTCS assessment periods – a suggested threat classification status has not been assessed by the NZTCS panel.
Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2017 | At Risk – Naturally Uncommon | Qualifiers: DP, RR, Sp
Previous conservation statuses
2012 | At Risk – Naturally Uncommon | Qualifiers: RR, Sp
2009 | At Risk – Naturally Uncommon | Qualifiers: DP
2004 | Gradual Decline
Distribution
Endemic to the North Island, where it is apparently only known from the Kaimanawa and Ruahine Ranges.
Habitat
Montane, subalpine to alpine river terraces, back swamps and on the margins of mires.
Features
Small, reddish, tufted sedge. Mature culms 100-200 mm, smooth, terete, basal sheaths grey-brown or light-brown. Leaves > culms, up to 350 mm long x 0.7-1.2 mm wide, plano or concavo-convex, reddish, margins scabrid, apex curled (cirrhose). Inflorescence of 4-6 sessile spikes, lower most distant, upper approximate. Terminal spike male, rest female, these usually with male flowers at the base. Spikes 5-10(-150) x 3-5 mm, ovate or cylindrical. Glumes = to or < urticles, broadly ovate or oblong, pale brown with light red markings, emarginate, green midrib forming a short scabrid awn < 0.5 (rarely 1 mm) long. Utricles 2 x 1-1.3 mm, ovoid to rhomboid, usually trigonous, yellowish and red near tip, glossy, faintly ribbed, beak minute, black or red-brown, smooth, crura entire or bidentate, scabrid. Stigmas 3. Nut 1 x 1 mm, elliptic-obovoid, trigonous, cream to dark brown.
Similar taxa
Carex druceana Hamlin (var. druceana in Flora of N.Z. Vol. II) has wider leaves, close packed spikelets (lower most rarely distant), glumes with awns up to 2 mm long, and by the utricles 2.5 x 1.3-1.5 mm. Both C. astonii and C. druceana resemble C. petriei in that they possess reddish, cirrhose-tipped leaves but both species lack the distinctive wide sheaths of C. petriei. Leaves of C. petriei are more rigid, the glumes more membranous, and the utricles are black except on the beak and stipe.
Flowering
No information available
Fruiting
No information available
Life cycle
Nuts surrounded by inflated utricles are dispersed by granivory and wind (Thorsen et al., 2009).
Propagation technique
Easy from fresh seed and the division of whole plants. Prefers moist soils, with a sunny aspect, free from weeds.
Threats
Rather local in its occurrences. Many of the habitats it was once recorded from in the 1950s and 1960s are now occupied by taller, faster growing weeds.
Etymology
carex: Latin name for a species of sedge, now applied to the whole group.
astonii: After Aston
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.
Thorsen, M. J.; Dickinson, K. J. M.; Seddon, P. J. 2009. Seed dispersal systems in the New Zealand flora. Perspectives in Plant Ecology, Evolution and Systematics 2009 Vol. 11 No. 4 pp. 285-309