Nomenclature
Scientific Name:
Ranunculus sceleratus L., Sp. Pl. 551 (1753)
Vernacular Name(s):
Celery-leaved buttercup; poison buttercup
 Description

Annual; roots all fibrous. Stems stout, erect, glabrous or with sparse appressed hairs, (10)–30–60–(75) cm tall. Basal and lower cauline lvs broadly ovate to reniform, cordate, deeply 3–(5)-lobed, glabrous or with fine appressed hairs, (1)–3–5–(8) × (1.5)–4–6–(10) cm; lobes obovate-cuneate, again shallowly 3-lobed and with crenate margins; petioles glabrous, (2)–5–10–(30) cm 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, 2.5–4–(6) cm long at fruiting. Sepals 5, hairy, deflexed, acute, 3–4 mm long. Petals 5, pale yellow, broadly obovate, 3–4 × 2.5 mm; nectary single, 0.5 mm from petal base, pocket-like. Receptacle elongated, cylindric, hairy. Achenes (100)–200–400–(700), in cylindric heads, glabrous, hardly flattened, weakly keeled, obovoid, weakly rugulose; body c. 1 × 0.8 mm; beak < 0.5 mm long.

[From: Webb et al. (1988) Flora of New Zealand. Volume 4.]

 Biostatus
Exotic
 Phenology

Flowering: (Aug.)–Oct.–Feb.–(May); Fruiting: (Aug.)–Oct.–Feb.–(May)

 Bibliography
Connor, H.E. 1977: The Poisonous Plants in New Zealand. Edition 2. Government Printer, Wellington.
Linnaeus, C. 1753: Species Plantarum. Impensis Laurentii Salvii, Stockholm.
Stewart, J. 1971: Plants in New Zealand Poisonous to Man. New Zealand Department of Health, Wellington.