Wood sorrel

The plant has trifoliate compound leaves, the leaflets heart-shaped and folded through the middle, that occur in groups of three on petioles up to 10cm long. It flowers from spring to midsummer with small white chasmogamous flowers with pink streaks. Red or violet flowers also occur rarely.During the night or when it rains the flowers close and the leaves fold.
As with other species of wood sorrel, the leaves are sometimes eaten. An oxalate called "sal acetosella" was formerly extracted from the plant, through boiling.