Ranunculus paucifolius
Common name
Castle Hill buttercup
Synonyms
Ranunculus crithmifolius subsp. pauciflorus (Kirk) F.J.F.Fisher; Ranunculus crithmifolius Hook.f. pro parte
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.
RANPAU
Chromosome number
2n = 48
Current conservation status
The threat classification 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) – more information about this can be found on the NZTCS website 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. Please note, threat classifications are often suggested by authors when publications fall between NZTCS assessment periods – a suggested threat classification status has not been assessed by the NZTCS panel.
Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2017 | Threatened – Nationally Critical | Qualifiers: CD, DP, OL
Previous conservation statuses
2012 | Threatened – Nationally Critical | Qualifiers: CD, OL
2009 | Threatened – Nationally Critical | Qualifiers: CD, OL
2004 | Not Threatened
Distribution
Endemic. New Zealand: South Island (Canterbury)
Habitat
Montane. Restricted to limestone colluvium and tallus in a gently sloping basin.
Features
Robust, summer-green, glabrous herb, up to 100 mm high. Rhizome up to 180 mm long, stout, sometimes branched, with thick vertical fibres; stock stout, erect or ascending, up to 40 mm long. Rosette leaves 1–20; lamina 20–70 × 20–60 mm, spreading, broadly reniform or broadly orbicular, grey to grey-green, often purplish, nearly entire or divided into 3–5 primary segments, segments usually shallow divided although occasionally up to 3/4 lamina depth, overlapping, margin finely dentate, base cuneate to subreniform; petiole 20–60 × 1.5–4.5 mm; sheath at base, broad. Scape 10–20 mm long, solitary, stout, naked, 1-flowered; reflexed at maturity. Flowers 20–50 mm diameter. Sepals 5, 8–11 × 4–6 mm, pale yellow, deflexed, ovate-oblong, apex subacute. Petals 5–10, 15–20 × 6–13 mm, golden yellow, broadly obovate, obovate to oblanceolate, apex obtuse to rounded, nectary 1–3 simple pits. Stamens 23–38; filament 3.5–5.0 mm long; anthers 1.8–2.2 mm long. Carpels 17–35. Achenes 3.0–4.2 mm long, brown; beak curved, laterally compressed, tapering toward apex.
Similar taxa
Most similar to R. crithmifolius from which it is distinguished by the leaves having three or occasionally five shallow and usually overlapping lobes that are rarely dissected to the base, the margins are finely and sharply toothed, and the base truncate to cuneate. In contrast, R. crithmifolius has leaves that are trifoliolate, each lobe is further divided for about one third of the depth, and the margins are more coarsely and deeply toothed to crenate.
Flowering
October–December
Flower colours
Yellow
Fruiting
November–January
Propagation technique
Difficult. Should not be removed from the wild.
Threats
A limestone endemic that is naturally restricted to a very small geographical area. Plants are vulnerable to browse damage from rabbits, hares and sheep, weeds are a constant threat, and seedlings are rarely seen.
Etymology
ranunculus: From the Latin ‘rana’ frog, meaning little frog and probably refers to the plants typical marshy habit where frogs abound
paucifolius: Few leaves
Where To Buy
Not Commercially Available
Attribution
Description based on Kirk (1899), Allan (1961), Fisher (1965) and herbarium specimens.