Ranunculus macropus


Ranunculus: From the Latin 'rana' frog, meaning little frog and probably refers to the plants typical marshy habit where frogs abound
macropus: big foot

Common Name(s)

Swamp buttercup

Current Conservation Status

2012 - Data Deficient

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 - Data Deficient
2004 - Gradual Decline


Ranunculus macropus Hook.f.



Flora Category

Vascular - Native

NVS Species 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.

Structural Class

Dicotyledonous Herbs other than Composites


Ranunculus longipetiolatus Colenso


Endemic to the North and northern South Islands. In the North Island formerly widespread from the northern Waikato south to Wellington. Most recent collections come from the western Waikato, Rotorua Lakes District and East Cape to Hawkes Bay. In the northern South Island, apparently always scarce, and there seem to have been no collections made over the last 20 or so years. Recently (2010) a population was found at Canadian Flats on the Taieri River in Otago.


Coastal to lowland. Usually found in raupo (Typha orientalis) dominated wetlands where it grows in still moderately deep to deep water.


Semi-aquatic to aquatic herb. Rosettes tufted on stout creeping stems. Basal leaves on very stout petioles (7-)15-30(-40) mm x 5-10 mm, arising from bulbous nodes. Leaves ternate (15-)-20-40(-80) mm wide, leaflets sessile or shortly stalked, cuneiform, shallowly 3-fid, apices crenate, serrate or entire, lateral leaflets slightly to distinctly larger than terminal, caulien leaves few, similar to basal but smaller. Flowers (1-)3-5 per stem, 10-15(-20) mm diam., pedicels galbrous. Sepals speading or weakly recurved, glabrous. Petals (1-)3-5(-7), dark yellow, oblong to broadly oblong, shortly clawed, nectary single, 0.5-1(-1.5) mm from petal base. Receptacle with basal collar of bristles. Achenes 15-50(-65), hardly flattened, glabrous 1.5-2 mm, beak straight, 1-1.5 mm long.

Similar Taxa

Confused with R. amphitrichus and R. glabrifolius. Species hybridizes with R. amphitrichus, the progeny of which are fertile (P. J. de Lange pers. obs.). Species is distinguished by the larger flower, with broad, irregularly spaced, oblong petals, whose nectary scale is virtually obscured by a dense cluster of carpels when viewed from above. In good habitat and growing conditions R. macropus is a very robust plant with very large, ternate leaves borne on stout petioles.


September - April (but sporadic flowering may occur at anytime of the year)

Flower Colours



October - July

Propagation Technique

Easy from the division of whole plants and from fresh seed. A wetland species which requires permanently damp but sunny situations, Good in shallow ponds.


Threatened by wetland drainage, modification and the spread of weeds. In large parts of its former range hybrids are now more commonly encountered than the actual species.

Chromosome No.

2n = 96

Endemic Taxon


Endemic Genus


Endemic Family


Where To Buy

Not commercially available.

Taxonomic notes

This species seems to be a shy flowerer, and is more often found in a sterile, vegetative state than reproductive. This trait is carried over into F1 hybrids. Hybrids are common wherever wetlands containing this species and R. amphitrichus have been modified, e..g, the wetlands of the lower Waikato. The taxonomic distinctiveness of Ranunculus macropus needs further study. It is truly, as Cheeseman (1925) makes clear a 'critical species'.



Fact Sheet prepared by P.J. de Lange (30 August 2003). Description based on Allan (1961), Webb et al. (1988) and fresh specimens

References and further reading

Allan, H.H. 1961: Flora of New Zealand. Vol. I. Wellington, Government Printer

Cheeseman, T.F. 1925: Manual of the New Zealand Flora. Wellington, Government Printer.

Webb, C.J.; Sykes, W.R.; Garnock-Jones, P.J. 1988: Flora of New Zealand. Vol. IV. Christchurch, DSIR Botany Division.

This page last updated on 14 May 2014