The New Zealand Plant Conservation Network

Species

Colobanthus squarrosus subsp. squarrosus

Etymology

Colobanthus: mutilated flower wth no petals

Common Name(s)

Colobanthus

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 - Range Restricted

Qualifiers

2012 - RR

Authority

Colobanthus squarrosus Cheeseman subsp. squarrosus

Family

Caryophyllaceae

Flora Category

Vascular - Native

NVS Species Code

COLSSS

Structural Class

Dicotyledonous Herbs other than Composites

Synonyms

None (described in 1999)

Distribution

Endemic. New Zealand: South Island (north-west Nelson, Kahurangi National Park)

Habitat

Alpine. On limestone-marble rock outcrops, cliffs, and talus slopes, less commonly found on skeletal, stony soils in sparse grassland.

Features

Plant a compact multi-branched cushion up to 700 mm diameter and 50-75 mm high (large cushions may be formed from the coalescence of several individuals). Branches leafy for much of length with c.5-8 pairs of green leaves and numerous persistent, pale brown dead leaves below; internodes 0.1-10.5 mm long. Leaves rigid, spreading to ascending and ± imbricate; sheath 0.6-2.5 mm long; blade subulate, 1.4—9.0 mm long (including the translucent tip), 0.6-1.4 mm wide, with colourless borders c.0.1 mm wide, becoming ± channelled when dry, gradually narrowed into a shortly acicular tip 0.3–0.9 mm long. Inflorescence a solitary flower on a bracteolate peduncle, lateral near branch apex. Flowers predominantly 5-merous, 3.5—5.5 mm diameter. Sepals 4-5, persistent, ovate, ovate-triangular or broadly ovate-triangular, 2.5–3.5 x 1.2—2.6 mm, margins ± membranous, keel not thickened, inconspicuous, predominantly white at anthesis (with a pale green median strip below) but becoming pale green at fruiting, the apex acute, occasionally cucullate, often with a small apiculus 0.1-0.4 mm long. Petals 0. Stamens 4-5, 3.0-7.8 mm long; anthers pale yellow. Ovary ovoid, white to yellowish at flowering becoming pale green at fruiting, ovules 9-44; styles 4 or 5, 1.5-3.5mm long. Peduncles ± hidden amongst leaves or shortly exserted at fruiting, 1.1-12.7mm long, with 1-3 pairs of foliose bracteoles; bracteoles 1.4-3.7 mm long with a short apiculate tip 0.1-0.4 mm long. Capsule splitting to c.½, 4- or 5-valved, valves from 1 mm shorter to 1 .5 mm longer than sepals. Seeds brown, shiny, colliculate dorsally to ± smooth laterally, ± obliquely reniform, 0.5–0.85 × 0.4–0.7 mm.

Similar Taxa

The subspecies forms larger cushions than any other New Zealand species of Colobanthus with the possible exception of C. muscoides. The predominantly white sepals of the flowers together with the usually strongly exserted stamens distinguish this subspecies from subspecies drucei and all the other New Zealand species of Colobanthus.

Flowering

November – January

Flower Colours

Green,White

Fruiting

January – March

Propagation Technique

Unknown in cultivation.

Threats

A Naturally Uncommon, Range-restricted, endemic of limestone/marble mountain ranges within Kahurangi National Park. There are no known threats.

Endemic Taxon

Yes

Endemic Genus

No

Endemic Family

No

Life Cycle and Dispersal

Winged seeds are dispersed by water and possibly also wind and ballistic projection (Thorsen et al., 2009).

This page last updated on 22 Jun 2014