Two-lipped yellow flowers with variable lip markings. Often many small red spots and one or more larger blotches.
Very similar to Monkey-flower, Mimulus guttatus but bracts usually distinctly toothed, lower corolla lobe angled downwards. Calyx and pedicels usually almost glabrous, but with some short, white hairs at angle of calyx base.
Can occur naturally or as a result of deliberate cultivation. Spreads vegetatively.
Damp or wet ground, streamsides, riverbanks. Most records from N, NE Ireland.
Confirmed by Paul Green