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 shallow ponds on mud, marshes and ditches, pools, and muddy places. The habit is prostrate, trailing. The stem floats or creeps on mud, and is stout, branched. There are no submerged leaves.
The aerial leaves are often opposite, kidney-shaped or rounded, heart-shaped, the 3-5 lobes deeply divided, widening from the base, very broad at the top, with 2-3 notches, not spotted, the lobes shallow, the base contracted. The stipules are broad, especially the upper, and large. The flowers are white, the petals twice as long as the calyx, oblong, narrow, inversely egg-shaped, 5-veined, distant. There are 8-10 stamens. The receptacle is not hairy. The style is terminal, central on the ovary. The achenes are numerous, hairless, unequally inversely egg-shaped, with a terminal point, the inner edge much rounded above, with slender, deciduous, nearly terminal style. The plant is creeping, or 4-12 in. long, flowering between June and August, and is a herbaceous perennial.
The habitat of this species is wet places. The plant is prostrate below, then ascending or creeping. The stems are sometimes rooting below, The leaves vary considerably, being hairy or not, egg - shaped or linear to lance - shaped, nearly entire or coarsely toothed, stalked, the lowest leaves stalked, the upper stalkless. The inter-nodes are straight. The flowers are shining yellow. The flower-stalk is furrowed. The achenes are inversely egg-shaped, pitted, shortly beaked, the style small, awl-like, forming a small head. The plant is 4-18 in. high, flowering from June to October, and is a herbaceous perennial.
The habitat of this plant is wet places. The habit is prostrate below, then erect. The root is fibrous. The stem is branched, tapering below, many - flowered, erect, hollow, furrowed. The leaves are egg-shaped, lance-shaped, the lower long-stalked, egg-shaped or heart-shaped, the upper stalkless, clasping, oblong. The plant is hairless. The flowers are small, yellow, the petals little longer than the sepals. The flower-stalks are furrowed. While the flowers of R. flammula are 3/4 in. in diameter, those of this species are 1/4 in. The achenes are small, hairy, granulate, obliquely egg-shaped, margined, withS a short terminal point or style. The plant is 6-10 in. high, flowering between June and August, and is a herbaceous annual.
The habitat of this species is wet sub-alpine spots. The habit is creeping, the plant rooting at the joints. It differs from the common form C. palustris in a few essentials. The radical leaves are triangular, acutely toothed, scalloped, small, obscurely 5-angled, blunt, below, or kidney-shaped. The base of the leaf is nearly at right angles to the stalk. The sepals are not touching and are narrow. The height of the plant is 8-14 in. It flowers between April and July, and is a herbaceous perennial.