Species

Caltha obtusa

Etymology

Caltha: From the Greek kalathos 'goblet', refers to the form of the flower
obtusa: blunt

Common Name(s)

White caltha

Current Conservation Status

2012 - Not Threatened

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 - Not Threatened
2004 - Not Threatened

Authority

Caltha obtusa Cheeseman

Family

Ranunculaceae

Flora Category

Vascular - Native

NVS Species Code

CALOBT

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.

Structural Class

Dicotyledonous Herbs other than Composites

Synonyms

Psychrophila obtusa (Cheeseman) W.A.Weber

Distribution

Endemic. South Island (from Canterbury southwards)

Habitat

In alpine flushes, seepages, around tarns and slow flowing streams. Also found seen in damp areas in open grassland and in similar sites in fell field and herb field

Features

Glabrous rhizomatous perennial herb of alpine flushes, seepages, bogs and stream sides. Plants forming a compact turf, when flowering with scapes 20-60 mm tall. Rhizomes stout, fleshy, shortly-creeping, white. Leaves radical, clustered; petioles 8-12 mm long, slender; lamina seldom 8-12 × 7.5-11.0 mm, dark green to yellow green, usually unblemished, sometimes marked with darker bronze blotches and/or streaks, broadly oblong to suborbicular, base 2-lobed, subcordate, apex emarginate, margins crenate to crenate-dentate; lobes upturned, ± appressed to and not much shorter than lamina, crenate. Scapes stout, initially subsessile to sessile, soon elongating, and then up to 60 mm tall. Sepals 5, 8-18 × 6-12 mm, white, obovate, obtuse to acute. Stamens 10-15; carpels narrow-ovate in outline; styles rather long, slender. Ripe heads 12-18 mm diameter. Seeds 2-5 per follicle, 1.2- 1.5 mm long, glossy red-brown to dark purple brown, ovate to broadly ovate, ovate-elliptic or elliptic.

Similar Taxa

Only reliably distinguished from other, small, alpine Ranunculus when flowering. From Caltha novae-zelandiae readily distinguished when flowering by the oblong-obovate white rather than linear-subulate yellow flowers, and vegetatively by the leaf margins which are crenate rather than shallowly sinuate to entire. Both Caltha obtusa and C. novae-zelandiae are easily distinguished from the uncommon, naturalised marsh marigold (C. palustris) by their much smaller size, turf-forming growth habit, ecology, and features of the foliage and flowers.

Flowering

December - February

Flower Colours

White,Yellow

Fruiting

February - April

Propagation Technique

Difficult. Can be grown in a pot but needs to be kept moist, free of bryophytes and algal growth. Needs plenty of light but resents high temperatures and humidity

Threats

Not Threatened

Endemic Taxon

Yes

Endemic Genus

No

Endemic Family

No

Where To Buy

Not commercially available

Taxonomic Notes

New Zealand plants had long been placed in the genus Caltha, they were then referred to Psychrophila, a decision which was over ruled on the basis of a detailed study by Schuettpelz & Hoot (2004).

Attribution

Fact sheet prepared for NZPCN by P.J. de Lange (28 March 2012). Description by P.J. de Lange.

References and further reading

Schuettpelz, E.; Hoot, S.B. 2004: Phylogeny and biogeography of Caltha (Ranunculaceae) based on chlroroplast and nuclear DNA sequences. American Journal of Botany 91(2): 247-253.

This page last updated on 13 Jan 2014