Ranunculus penicillatus is variable with respect to its leaves (presence or absence of laminar leaves) and leaf characteristics; it exits as two subspecies (ssp penicillatus, ssp pseudofluitans) the former with two varieties (var penicillatus, var vertumnus).
Main flower color:
Ireland, Wales, England and the southern third of Scotland
A few cm
Fast flowing streams, especially on chalk soils
Up to 45 mm across - larger than other UK water crowfoots, with five white petals, yellow at the centre, around a cluster of yellow stamens and carpels
Submerged leaves are divided up to three times into thread-like segments. Floating laminar leaves may also be present, shallowly divided into three rounded lobes
May to July