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.
This pretty plant is quite rare, being found, south of Perth, in only eight counties, and in the Channel Islands. It occurs also elsewhere as a casual. The habitat is pasture-land of a sandy or gravelly nature. It has an erect habit, the stem being simple. The flowers are borne in a cluster, and the scales of the calyx are membrane-like and almost transparent. The flowers are small, rose-coloured, and open singly. The plant may be as much as j8 in. in height, but is usually less. From June onwards it may be found in flower up till October, but is at its best in July. It is an annual. The anthers ripen first, and the flowers are pollinated by butterflies. The seeds are dispersed by the wind, the capsule having the censer type of structure, opening above. It is not sufficiently large to find a place in the garden.
Much commoner than the last, this pink is found in half of the counties, being a purely European species, whereas the last is found in Asia and has been introduced into the United States. The habitat is similar, but it is often found on banks, usually on dry soil, and commonly on hilly pastures. The flowers are single, and the scales of the calyx equal the tube. The stem and leaves are downy and rough. The flower is rosy-white, and has no smell. The dark circle round the mouth of the corolla may serve as a honey-guide. The flowers bloom from June to September. The pollination and dispersal are as in the last. No use is made of this plant. It is about a foot high. The soil is a sandy loam.