Greater Stitchwort (Stellaria holostea). Another lovely spring wildflower. This plant is a spreader laying out a mass of little white flowers on low growing foliage which has a fresh, grassy look to it.
 I planted several plugs of it a few years ago in a shady border (see top photo) and it has proved ideally suited to covering the bare ground, weaving round other plants as it steadily increases.
 The other two photos show S. holostea in its natural habitat which is the hedgerow and woodland edge. In this instance I spotted it growing along a perimeter fence at Butcher's Wood in West Sussex.