The New Zealand Plant Conservation Network

Species

Carex astonii

Etymology

Carex: Latin name for a species of sedge, now applied to the whole group.
astonii: after Aston

Common Name(s)

Astons Sedge

Current Conservation Status

2012 - At Risk - Naturally Uncommon

Conservation status of New Zealand indigenous vascular plants, 2012
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2012 using the New Zealand Threat Classification System (NZTCS). This report includes a statistical summary and brief notes on changes since 2009 and replaces all previous NZTCS lists for vascular plants. Authors: Peter J. de Lange, Jeremy R. Rolfe, Paul D. Champion, Shannel P. Courtney, Peter B. Heenan, John W. Barkla, Ewen K. Cameron, David A. Norton and Rodney A. Hitchmough. File size: 792KB

Previous Conservation Status

2009 - At Risk - Naturally Uncommon
2004 - Gradual Decline

Qualifiers

2012 - RR, Sp
2009 - DP

Authority

Carex astonii Hamlin

Family

Cyperaceae

Flora Category

Vascular - Native

NVS Species Code

CRXAST

Structural Class

Sedges

Synonyms

Carex druceana var. astonii (Hamlin) Edgar

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

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.

Chromosome No.

2n = c.60

Endemic Taxon

Yes

Endemic Genus

No

Endemic Family

No

Life Cycle and Dispersal

Nuts surrounded by inflated utricles are dispersed by granivory and wind (Thorsen et al., 2009).

 

 

    

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

This page last updated on 26 May 2014