Caltha obtusa
Common name
White caltha
Synonyms
Psychrophila obtusa (Cheeseman) W.A.Weber
Family
Ranunculaceae
Flora category
Vascular – Native
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Structural class
Herbs - Dicotyledons other than Composites
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.
CALOBT
Current conservation status
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2017 using the New Zealand Threat Classification System (NZTCS). This report includes a statistical summary and brief notes on changes since 2012 and replaces all previous NZTCS lists for vascular plants. Authors: By Peter J. de Lange, Jeremy R. Rolfe, John W. Barkla, Shannel P. Courtney, Paul D. Champion, Leon R. Perrie, Sarah M. Beadel, Kerry A. Ford, Ilse Breitwieser, Ines Schönberger, Rowan Hindmarsh-Walls, Peter B. Heenan and Kate Ladley.
2012 | Not Threatened
Previous conservation statuses
2009 | Not Threatened
2004 | Not Threatened
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
Etymology
caltha: From the Greek kalathos ‘goblet’, refers to the form of the flower
obtusa: Blunt
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.
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Caltha obtusa Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/caltha-obtusa/ (Date website was queried)