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 plant is wet and boggy places, swamps, and bogs. The habit is the loose rosette habit. The rootstock is stoloniferous, the stolons underground, rooting, with stipules and leaves at the nodes. The stipules are egg-shaped to lance-shaped, membranous, with glandular teeth. The leaves are few, heart-shaped to kidney-shaped, entire, hairless, or rarely hairy. The flowers are few, scentless, pale or dark lilac, with dark branching veins. The sepals are oval, blunt, with membranous borders. The spur is flat, blunt, longer than the calyx appendages. The anther-spurs are curved, short, and thick. The stigma is flattened. The capsule is hairless, nodding. The fruit-stalk is erect. The plant is 3-6 in. high, flowering from April to July, and is a herbaceous perennial.
The habitat of this plant is bogs, fens, turf bogs. The habit is the loose rosette habit, soboliferous. The rootstock is creeping, horizontally, with distinct plants at the internodes, suberect, and branched. The lower stipules are brown, narrow, nearly entire, the middle ones green, lance-shaped, toothed or nearly entire, not half as long as the stalks, the upper shorter, narrower, long-pointed. The lower leaves are oblong to lance - shaped, more or less heart-shaped, blunt below, the leafI stalks often irregularly winged above, longer than the blades, the middle with blades longer than the leaf-stalks, the upper narrowed to an acute blunt apex, pale-green, hairless, cut or toothed. The flowers are small, blue or nearly white, round in outline, the sepals egg-shaped to awl-shaped, with a white margin, the bracts slender near the curvature of the spur. The spur is green, little longer than the calycine appendages, the anther spurs short, curved, nearly as broad as long. The capsule is hairless, egg-shaped, acute, bluntly 3-angled. The plant is 2-6 in. high, flowering in May and June, and is a herbaceous perennial.