Stellaria aquatica

About

Stellaria aquatica is a species of flowering plant in the carnation family Caryophyllaceae, known as water chickweed or giant chickweed. It is a perennial herbaceous dicot plant with stems between 10 and 100 cm high, growing in humid, wet areas, for example, on the sides of gutters or under or between bushes. It occurs naturally in the temperate regions of central and western Europe. The flowers are white. The plants bloom between June and August.

Summary from Wikipedia