Scutellaria galericulata L.
Plant Height 30-50 cm. Flower length 1-1.8 cm.
This is relatively a small native perennial and may be easily overlooked. The bright violet-blue flowers occur sparingly and in pairs. The leaves are opposite, oval to lance-shaped, with blunt-toothed margins.
It flowers June to September and is found in damp places like wet meadows, marshes, along rivers, streams, ditches and canals. Fairly common and widespread throught Britain except in north of Scotland.