Colobanthus squarrosus subsp. squarrosus
Common names
colobanthus
Biostatus
Native – Endemic taxon
Category
Vascular
Structural class
Herbs - Dicotyledons other than Composites
Flower colours
Green, White
Detailed description
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.
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.
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
Threats
A Naturally Uncommon, range-restricted, endemic of limestone/marble mountain ranges within Kahurangi National Park. There are no known threats.
Detailed taxonomy
Family
Synonyms
None (described in 1999)
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Ecology
Flowering
November – January
Fruiting
January – March
Life cycle and dispersal
Winged seeds are dispersed by water and possibly also wind and ballistic projection (Thorsen et al., 2009).
Propagation technique
Unknown in cultivation.
Other information
Etymology
colobanthus: Mutilated flower wth no petals
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.
COLSSS
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: RR
2012 | At Risk – Naturally Uncommon | Qualifiers: RR
2009 | At Risk – Naturally Uncommon
2004 | Range Restricted
Referencing and citations
References and further reading
Sneddon B.V. 1999: The taxonomy and breeding system of Colobanthus squarrosus (Caryophyllaceae). New Zealand Journal of Botany 37: 195-204.
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 11: 285-309.
Attribution
Description modified from Sneddon (1999).