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 brooks, marshes, watery places. The habit is tufted. The plant is pale-green, limp, branched. The stem is short, rigid, erect. The leaves are opposite, spoon-shaped, entire, not free at the base. The flowers are white, very small, drooping, then erect, the flower-stalks terminal and axillary. The bracts have a membranous border. The petals exceed the blunt sepals. The capsule is inversely egg-shaped. The valves are rolled longitudinally inwards after the seeds fall. The seeds are shining, netted, rough. The plant is 1-3 in. high, flowering between May and August, and is a herbaceous annual.
Montia lamprosperma, Cham. = M. fontana, L. vera. - The habitat is wet places, wet heaths. The stem is limp, more or less erect. The leaves are free below. The flowers are white, small. The seeds are chestnut-brown, shining, netted, with obscure tubercles. The plant is 3-8 in. high, flowering from May to August, and is a herbaceous annual.