Summer brings white clouds! Not just to the sky though, you can find 'clouds' of white flowered hedge bedstraw (Galium mollugo) along wayside banks and hedgerows across Dorset although rarely on heathland, it prefers a neutral or chalky soil. It occurs across much of Europe too and also in the United States where in some places it is classified as an obnoxious weed. A little harsh perhaps but I did describe it as vigorous and I am not sure you would want to plant it in your garden. It can climb over anything that gets in its way.
Hedge bedstraw is a vigorous plant that produces several stems and each has dense clusters of small creamy white flowers. Each flower is tiny and rather insignificant but together they make a lovely show. It flowers from late May right through until early autumn depending on position and competition from other plants but in general I think it is at its best in July.
Many species of the galium family are known as bedstraws because once they were harvested and dried for use as bedding which in these days of sprung mattresses comes as something of a surprise to me! I cannot believe it was very comfortable.