About Ranunculus amphitrichus Colenso
Ranunculus amphitrichus Colenso, commonly called small river buttercup, is an aquatic perennial plant. Its stems grow out from leaf clusters, and are either smooth or sparsely covered in soft, weak, thin hairs. Its leaves are glossy green, roughly circular, between 1 and 10 cm (0.39–3.94 in) across, and lobed; the leaves sometimes float, and their petioles measure 5–24 cm (2.0–9.4 in) long.
Yellow flowers develop on stems that are either simple or branched, with these stems reaching 7–35 cm (2.8–13.8 in) long. Flowers usually have five petals, which are narrowly oblanceolate or oblong and wedge-shaped at the base; petals are 3–5 mm (0.12–0.20 in) long and 0.8–1.8 mm (0.031–0.071 in) wide. This species flowers from December to March. Its fruit is a green achene that is densely covered with soft, weak hairs.
This plant grows in shallow water within swamps, lakes, and slow-flowing streams. Its known distribution includes Western Australia, South Australia, New South Wales, Tasmania, the Australian Capital Territory, and New Zealand.
