Carex astonii
Common names
Aston’s sedge
Biostatus
Native – Endemic taxon
Category
Vascular
Structural class
Sedges
Detailed description
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 × 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) × 3–5 mm, ovate or cylindrical. Glumes ≤ utricles, 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 × 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 × 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 utricles 2.5 × 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.
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.
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: RR, Sp
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.
Detailed taxonomy
Family
Synonyms
Carex druceana var. astonii (Hamlin) Edgar
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Ecology
Flowering
No information available
Fruiting
No information available
Life cycle and dispersal
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.
Other information
Etymology
carex: Latin name for a species of sedge, now applied to the whole group.
astonii: After Aston
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
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: DP, RR, Sp
2012 | At Risk – Naturally Uncommon | Qualifiers: RR, Sp
2009 | At Risk – Naturally Uncommon | Qualifiers: DP
2004 | Gradual Decline
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.
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.
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.