Short to medium almost hairless plant. Stem hollow, ascending to erect. Leaves oval, irregularly toothed, only the lower stalked. Flowers bright yellow, usually with reddish brown spots in the mouth, 25 to 45 mm long, the corolla mouth closed by two hairy ridges on the lower lip, flower stem glandular-hairy.

Wet and marshy habitats, river and lake margins.

July to September.

Perennial

Widespread but local in Britain.

Local in Leicestershire and Rutland. In the 1979 Flora survey of Leicestershire it was found in 12 of the 617 tetrads.