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 violet is sandy shores and dunes. The habit is creeping. There is no rootstock. The stems are rough, angular, and the plant is branched, tufted, stoloniferous. The lower part of the stipule is lengthened, separating the lateral lobes. The petals are not much longer than the sepals, spreading, blue, purple, or yellow. The capsule is 3-angled. The plant is 1-5 in. high, flowering between May and July, and is a herbaceous perennial.