Chickweed

Chickweed is a fast-growing, low-spreading annual weed with tiny white star-shaped flowers that thrives in cool, moist soil and can quickly take over garden beds and lawns.
Stellaria Media (Starweed)
Origin: Europe (now widespread across North America)
USDA Hardiness Zones: 3-9
Pros:
Edible and medicinal – young leaves are edible and used in traditional herbal remedies
Grows in poor soil – can act as a living mulch in some garden settings
Cons:
Rapid spread – grows and reseeds aggressively, especially in cool seasons
Smothers other plants – forms dense mats that crowd out garden crops and flowers
David Kim