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 roadsides, hedges, riverbanks, fields, banks of streams on the borders of Wales, etc, in which last case it may be indigenous. The habit is erect. The rootstock is white, fleshy, stoloniferous. The stem is stout, leafy, straight, ascending. The plant is hairless, bluish-green. The leaves are oblong, lance-shaped, 3-ribbed, the upper sheathing, united below. The flowers are in a cvme or panicled corymb, large, pale-pink or white. The petals are inversely heart-shaped, with a long narrow claw, crowned, notched, the calyx cylindrical, not angled. The capsule is egg-shaped. The seeds are kidney-shaped. The plant is 1-3 ft. high, flowering in August and September, and is a herbaceous perennial.
The habitat of this species is roadsides, fields, and waste places. The habit is erect. The plant is branched, bluish-green except in the axils, where rain collects and is probably absorbed, smooth as a rule. The stem is erect, with no barren prostrate stems. The leaves are hairless, egg-shaped or inversely so, oblong, or elliptic to lance-shaped. The bracts have a membranous border. The flowers are white, terminal, panicled, the branches unequal, numerous, drooping, the petals deeply cleft, rarely crowned, with narrow lobes, the calyx inflated (hence infiata), netted, the mouth narrower than the base. The capsule is rounded, conical above. The plant is 1-3 ft. high, flowering from June to August, and is a herbaceous perennial.
The habitat of this species is hedgebanks, moist copses, woods, damp shady places. The habit is prostrate. The stem is limp, weak, branched, with spreading hairs. The leaves are stalked egg-shaped, acute, 3- or rarely 5-nerved (hence trinervis in the first case), fringed with hairs, like the stalks, the upper staikless. The flowers are small, in the axils, solitary, or in a cyme, long-stalked, the stalks slender and spreading at length, white. The petals are inversely egg-shaped, lance-shaped. The sepals are 3-ribbed, the lateral veins faint, the intermediate rib strongest, rough, lance-shaped, longer than the petals. There are 10 stamens, or the plant may rarely be pentandrous. The capsule is nearly round, included in the calyx, the seeds smooth, with an arillus. The plant is 6-12 in. long, flowering in May and June, or as late as November, and is an annual.