Vascular – Exotic
Dicotyledonous Herbs other than Composites
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.
Fleshy, shiny-leaved buttercup, superficially looking like a young celery plant, but with small (0.5 to 1 cm diameter) 5-petalled pale yellow flowers and a cylindrical green fruit on a many branched flowerhead on the top of upright leafy stem (up to 60 cm tall).
Scattered throughout both islands.
Grows in wet places such as in ditches, along streams and around ponds and lakes (Landcare Research 1999).
Annual; roots all fibrous. Stems stout, erect, glabrous or with sparse appressed hairs, (0.10-)0.30-0.60(-0.75) m tall. Basal and lower cauline lvs broadly ovate to reniform, cordate, deeply 3(-5)-lobed, glabrous or with fine appressed hairs, (10-)30-50(-80) × (15-)40-60(-100) mm; lobes obovate-cuneate, again shallowly 3-lobed and with crenate margins; petioles glabrous, (20-)50-100(-300) mm long. Upper cauline lvs similar; lobes becoming lanceolate, entire; uppermost lvs subsessile, not lobed, becoming finely appressed-hairy. Fls usually > 30 per stem, 6-10 mm diam. Pedicels erect, numerous, with sparse, fine hairs, sulcate, 25-40(-60) mm long at fruiting. Sepals 5, hairy, deflexed, acute, 3-4 mm long. Petals 5, pale yellow, broadly obovate, 3.0-4.0 × 2.5 mm; nectary single, 0.5 mm from petal base, pocket-like. Receptacle elongated, cylindric, hairy. Achenes (100-)200-400(-(00), in cylindric heads, glabrous, hardly flattened, weakly keeled, obovoid, weakly rugulose; body c.1.0 × 0.8 mm; beak < 0.5 mm long
Differs from other buttercups by the combination of glabrous deeply 3 to 5 lobed leaves, upright not creeping growth habit, deflexed sepals and cylindric rather than globose receptacle.
Spring to autumn
Spring to autumn
Seed dispersed by water, animals or contaminated machinery.
Europe, South, West and Central Asia, Northern and tropical Africa
Reason for introduction
Unknown, seed or soil contaminant
Can be controlled manually, mechanically or herbicidally depending on situation.
ranunculus: From the Latin ‘rana’ frog, meaning little frog and probably refers to the plants typical marshy habit where frogs abound
Resembles celery so sometimes mistakenly eaten. One of the most toxic buttercup species with the divided leaves causing blistering of the mouth and lips.
Factsheet prepared by Paul Champion and Deborah Hofstra (NIWA).
References and further reading
Webb, C.J.; Sykes, W.R.; Garnock-Jones, P.J. (1988). Flora of New Zealand Volume 4: Naturalised pteridophytes, gymnosperms, dicotyledons. Botany Division, DSIR, Christchurch.
Popay et al (2010). An illustrated guide to common weeds of New Zealand, third edition. NZ Plant Protection Society Inc, 416pp.
Johnson PN, Brooke PA (1989). Wetland plants in New Zealand. DSIR Field Guide, DSIR Publishing, Wellington. 319pp.
Healy, A.J. (1982). Identification of weeds and clovers. New Zealand Weed and Pest Control Society Publication. Editorial Services Limited, Featherston. 299pp.