Lesser (grass-leaved) Stitchwort (Stellaria graminea), fam. Caryophyllaceae.
Narrow leaves, branching at sharp angle from the stem, and the ability to form thick grassy shrubs make this plant vaguely similar to cereal grasses. However, the stitchwort has no relation to them, which is easy to realize even from the appearance of a non-flowering plant – its leaves are arranged oppositely, which never happens with true grasses.
Small white flowers, appearing in spring, most often have five petals, each of them being split in two parts almost down to the base. So, it seems like there are ten petals. Sometimes four-petal flowers occur (they look like eight-petal).
Lesser Stitchwort grows in the forest along the roads, quite rarely. Unlike the edible and beneficial Common Chickweed, this species is toxic ("drunken herb"), it evokes sickness of the cattle, including the cases when it is contained in dry fodder hay.