Stellaria graminea aka Common Stitchwort

Stellaria graminea, commonly known as common starwort, grass-leaved stitchwort, lesser stitchwort, and grass-like starwort, is a rhizomatous perennial herb in the family Caryophyllaceae. It has slender, brittle shoots that arise from a creeping rootstock and can reach up to 90 centimeters in length. The stems are four-angled, weak, and hairless, adorned with pairs of linear or lance-shaped leaves that are smooth-edged and mostly hairless, except for some hairs lining the bases. In late spring and summer, this plant produces loose sprays of starry white flowers, each 6-10 centimeters across. The flowers have five green sepals lined with hairs and five deeply lobed white petals that give the appearance of being two. The plant bears reddish-brown seeds, measuring 1 millimeter in diameter, and has 10 stamens. It is important to note that this plant might be poisonous.