Ranunculus acris L.
giant buttercup
Perennial; roots all fibrous, arising from a stout short rhizome. Stems stout, erect, hairy at least below, (30)-60-100 cm tall. Lvs subcircular to rhomboid, very deeply palmately 5-lobed; lobes pinnatifid with narrowly lanceolate acute segments, hairy; lower lvs 4-12 × 5-15 cm on hairy petioles 10-50 cm long; uppermost lvs becoming sessile, not lobed, entire, linear. Fls numerous per stem, 15-20-(30) mm diam. Pedicels erect, with spreading hairs, terete, 2-6 cm long. Sepals 5, hairy, spreading, 4-5 mm long. Petals 5, yellow, obovate, 10-12 × 8-10 mm; nectary single, c. 1 mm from petal base, covered by a short oblong truncate or retuse scale. Receptacle glabrous. Achenes 30-50, glabrous, strongly flattened, bordered, obovate-deltoid to subcircular; body 2.5-3 × c. 2 mm; face smooth; beak hooked, c. 0.5 mm long.
N.: Northland, Auckland, Waikato, Bay of Plenty, Volcanic Plateau, Hawke's Bay, Wairarapa, Taranaki, Manawatu; S.: Nelson, Canterbury, Westland, Otago, Southland, Fiordland; St.
Europe, N. Asia 1872
Waste land, roadsides, river flats, pasture, swamp margins.
FL (Oct)-Nov-Apr FT (Nov)-Dec-Apr.
Possibly poisonous (Connor 1977).
N.Z. specimens are referable to subsp. acris. Double-flowered cvs are rarely found growing wild.
