The New Zealand Plant Conservation Network

Species

Ranunculus paucifolius

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

Common Name(s)

Castle Hill buttercup

Current Conservation Status

2012 - Threatened - Nationally Critical

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 - Threatened - Nationally Critical
2004 - Not Threatened

Qualifiers

2012 - CD, OL
2009 - CD, OL

Authority

Ranunculus paucifolius Kirk

Family

Ranunculaceae

Flora Category

Vascular - Native

NVS Species Code

RANPAU

Structural Class

Dicotyledonous Herbs other than Composites

Synonyms

Ranunculus crithmifolius subsp. pauciflorus (Kirk) F.J.F.Fisher; Ranunculus crithmifolius Hook.f. pro parte

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

Chromosome No.

2n = 48

Endemic Taxon

Yes

Endemic Genus

No

Endemic Family

No

This page last updated on 31 Jul 2014