Ranunculus stylosus
Biostatus
Native – Endemic taxon
Category
Vascular
Structural class
Herbs - Dicotyledons other than Composites
Flower colours
Green, Yellow
Detailed description
Perennial herb forming solitary appressed rosettes or small patches in exposed habitats but in sheltered sites producing tufts up to 50 mm tall. Petioles 15-40 mm long, dark green, mottled with dark-purple, broadly-sheathing, scarious with ciliate bases. Leaves 9-14 x 9-14 mm, glossy dark green, broad-ovate to deltoid, simple, crenately lobed or toothed, or cut deeply to 1/2 way into main 3 lobes; lamina rigidly coriaceous, covered in pale buff hairs. Flowers solitary, 15-20 mm diameter; peduncles 20-40 mm long, stout, decumbent to ascending, dark green, mottled purple or purple throughout, very hairy, bracts 1-2 at base, these simple, narrow; sepals 5, fugaceous, green-margined, dark brown to near black beneath; petals 5-7, rather narrow, 7-10 x 3-4 mm, dark glossy yellow above, often blotched orange-brown to dark brown beneath; nectary near petal base, covered by oblong scale; stamens 15-20; receptacle sparsely hairy. Achenes 4-6, 3-5 mm long, brown blotched with dark brown, turgidly ellipsoid, beak slender, 2-2.5 mm, only slightly curved.
Similar taxa
Closest to R. kirkii Petrie which is another Stewart Island endemic, from which R. stylosus differs by its rather thick, simple to 3-lobed (never ternate) leaves, much larger, solitary flowers, the near basal nectary, and narrower, turgid rather than flattened achenes with long (2-2.5 cf 0.5-1.2) usually only slightly curved beaks.
Distribution
Endemic. Stewart Island (southern part): Tin Range, Deceit Peaks, Mt Rakeahua.
Habitat
Subalpine (> 500 m a.s.l.) favouring rocky or open windswept shrubland, grassland and herbfield.
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.
Please note, threat classifications are often suggested by authors when publications fall between NZTCS assessment periods – these interim threat classification statuses has not been assessed by the NZTCS panel.
- 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 | At Risk – Naturally Uncommon | Qualifiers: OL
Threats
Not Threatened. A narrow range endemic that it is often locally common within the small geographic area it naturally occupies.
Detailed taxonomy
Family
Ranunculaceae
Synonyms
None
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Ecology
Flowering
December - January
Fruiting
December - March
Propagation technique
Easily grown in a pot or rock garden and reasonably tolerant of humidity and excessive moisture. Requires cold treatment to flower, and is very prone to powdery mildew in humid or damp, warm climates.
Other information
Where To Buy
Not commercially available
Etymology
ranunculus: From the Latin ‘rana’ frog, meaning little frog and probably refers to the plants typical marshy habit where frogs abound
Chromosome number
2n = 48
Previous conservation statuses
2017 | At Risk – Naturally Uncommon | Qualifiers: OL
2012 | At Risk – Naturally Uncommon | Qualifiers: OL
2009 | At Risk – Naturally Uncommon
2004 | Range Restricted
Referencing and citations
References and further reading
Wilson, H.D.; Garnock-Jones, P.J. 1983: Taxonomic notes on Stewart Island Ranunculus including two new species. New Zealand Journal of Botany 21: 341-345.
Attribution
Fact Sheet prepared for the NZPCN by P.J. de Lange (14 April 2006). Description adapted from Wilson & Garnock-Jones (1983).
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Ranunculus stylosus Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/ranunculus-stylosus/ (Date website was queried)