Ranunculus acaulis
Common names
sand buttercup, shore buttercup
Biostatus
Native
Category
Vascular
Structural class
Herbs - Dicotyledons other than Composites
Flower colours
Green, Yellow
Detailed description
Perennial, mat-forming; rosettes tufted along pale, spreading, slender rhizomes. Leaves long-petiolate; lamina dark bronze-green to dark green, fleshy, glabrous, trifoliolate or deeply 3-lobed, 5–15–(20) mm diameter; lobes bluntly obovate, entire to shallowly toothed, terminal lobe entire or 3-fid, rounded to obtuse at apex, lateral lobes entire or with 1 basiscopic lobe. Flowers solitary, 5–10 mm diameter; scapes ± sessile, or very short, peduncles glabrous. Sepals spreading, glabrous. Petals 5–8, greenish-yellow, narrowly oblong or spathulate; nectary single, 1.5–2.0 mm from petal base, pocket-like. Receptacle glabrous. Achenes (6)–10–12–(30), not flattened, glabrous; body 2–3 mm long; beak straight, 0.5–1.0 mm long.
Similar taxa
Distinguished from other buttercups by the glabrous receptacle, fleshy, obovate, entire, bluntly toothed or shallowly lobed leaves with the apex of the terminal lobe rounded or broadly obtuse, and by the straight achene beak.
Distribution
Indigenous. New Zealand: North Island, South Island, Stewart Island/Rakiura, Chatham Islands, Auckland Islands. Also Australia (Tasmania), South America (Chile) and the Falkland Islands.
Habitat
Coastal and occasionally inland. Usually in saltmarsh or meadow, muddy ground near tidal creeks, on rock platforms or rock stacks, occasionally on salt pans, limestone bluffs and along lake margins.
Current conservation status
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2022-2023 using the New Zealand Threat Classification System (NZTCS) – more information about this can be found on the NZTCS website. This report includes replaces all previous NZTCS lists for vascular plants. Previous assessments can be found here.
- Conservation status of vascular plants in Aotearoa New Zealand, 2023. 2024. Peter J. de Lange, Jane Gosden, Shannel P. Courtney, Alexander J. Fergus, John W. Barkla, Sarah M. Beadel, Paul D. Champion, Rowan Hindmarsh-Walls, Troy Makan and Pascale Michel Department of Conservation. Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2023 | Not Threatened | Qualifiers: SO
Detailed taxonomy
Family
Synonyms
Ranunculus petriei Allan
Endemic taxon
No
Endemic genus
No
Endemic family
No
Ecology
Flowering
August–April
Fruiting
September–July
Propagation technique
Easily grown from rooted pieces and fresh seed. An attractive pot plant.
Wetland plant indicator status rating
Information derived from the revised national wetland plant list prepared to assist councils in delineating and monitoring wetlands (Clarkson et al., 2021 Manaaki Whenua – Landcare Research Contract Report LC3975 for Hawke’s Bay Regional Council). The national plant list categorises plants by the extent to which they are found in wetlands and not ‘drylands’. The indicator status ratings are OBL (obligate wetland), FACW (facultative wetland), FAC (facultative), FACU (facultative upland), and UPL (obligate upland). If you have suggestions for the Wetland Indicator Status Rating, please contact: [Enable JavaScript to view protected content]
FACW: Facultative Wetland
Usually is a hydrophyte but occasionally found in uplands (non-wetlands).
Other information
Etymology
ranunculus: From the Latin ‘rana’ frog, meaning little frog and probably refers to the plants typical marshy habit where frogs abound
acaulis: From the Greek a-, without; kaulos, stalk, stem, meaning stemless, or seemingly so.
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.
RANACA
Chromosome number
2n = 48
Previous conservation statuses
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2022-2023 using the New Zealand Threat Classification System (NZTCS) – more information about this can be found on the NZTCS website. This report includes replaces all previous NZTCS lists for vascular plants. Previous assessments can be found here.
- Conservation status of vascular plants in Aotearoa New Zealand, 2023. 2024. Peter J. de Lange, Jane Gosden, Shannel P. Courtney, Alexander J. Fergus, John W. Barkla, Sarah M. Beadel, Paul D. Champion, Rowan Hindmarsh-Walls, Troy Makan and Pascale Michel Department of Conservation. Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2017 | Not Threatened | Qualifiers: SO
2012 | Not Threatened
2009 | Not Threatened
2004 | Not Threatened
Regional conservation statuses
The regional threat classification system leverages off the national assessments in the NZTCS, providing information relevant for the regional context. Otago conservation status information is sourced from the “Regional conservation status of indigenous vascular plants in Otago” Jarvie S et al. (2024) report.
Otago: 2024 | Regionally Not Threatened
Referencing and citations
Attribution
Fact sheet prepared by P.J. de Lange (1 June 2013).
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Ranunculus acaulis Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/ranunculus-acaulis/ (Date website was queried)