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 barren sandy heaths in the south and east. The plant has the cushion habit, and is prostrate, then ascending, growing in tufts, and is of a red colour. The stems are branched, smooth, with slender branches, leaf)', and all bear flowers. The leaves are thick, oblong, opposite, hollow above, blunt or with a short point, united below. The flowers are white with red tips, sessile or stalkless, in the axils, 3-cleft. The parts of the flower are rarely in fours. The sepals are ovate, with a long, narrow point, acute, and green. The petals are small, awl-like. There are no scales. The follicle is constricted, and 2-seeded. The plant is 1-2 in. high, and flowers in June and July. It is an annual.