Chickweed

Stellaria media, chickweed, is a cool-season annual plant native to Europe, which is often eaten by chickens. It is sometimes called common chickweed to distinguish it from other plants called chickweed. Other common names include chickenwort, craches, maruns, winterweed. The plant germinates in fall or late winter, then forms large mats of foliage. Flowers are small and white, followed quickly by the seed pods. This plant flowers and sets seed at the same time. from Wikipedia