This section is from the book "British Wild Flowers - In Their Natural Haunts Vol5-6", by A. R. Horwood. Also available from Amazon: A British Wild Flowers In Their Natural Haunts.
The habitat of this species is boggy places. The habit is prostrate. The stolons are not subterranean. The stem is somewhat angular, with spreading hairs. The leaves are rather acute. The flowers are pale-blue, in a somewhat leafy raceme, with 1-4 leaves below. The limb of the corolla is flat and longer than the tube, the lobes slightly notched. The calyx is divided half-way down, with closely pressed hairs, and in fruit is open, the teeth narrow, lance-shaped, acute, and exceeding the corolla-tube. The style is not so long as the calyx. The 4 nutlets are small. The plant is creeping, flowering between June and August, and is a herbaceous perennial.