Up to 40 or 50 cm tall with creeping stems rooting at the base then ascending, thick and fleshy. Flowers pale to dark blue, 5 to 8 mm in opposite long-stalked racemes rising from the bases of the upper leaves.

Glabrous, with racemes of blue flowers in leaf axils; wet places

Wet habitats such as stream, lake and pond margins.

May to September.

Perennial.

Common throughout Britain.

Common in Leicestershire and Rutland. In the 1979 Flora survey of Leicestershire it was found in 529 of the 617 tetrads.

In the current Checklist (Jeeves, 2011) it is listed as Native, Frequent