Stellaria media
Family: 
Caryophyllaceae
Life Cycle: 
Annual
Plant status: 
Weed
Habit: 
Common chickweed is mostly prostrate, and often grows erect by growing on top of itself, forming small mounds or mats. Foliage is opposite, simple, and ovate to elliptical. Foliage is generally glabrous (without hairs), although the petioles are hairy, and sometimes the base of the leaf is as well.
Flowers: 
White ½” flowers are produced in clusters at the terminal end of the stem. Each flower has 5 petals, each so deeply bi-lobed that it appears to have 10 petals. Flowering occurs in the spring.
Favorable environments: 
Field
Favorable environment notes: 
Common chickweed can grow in a variety of locations. It prefers fertile, moist disturbed sites such as ornamental plantings, lawn areas, gardens and field nurseries. It also thrives in many agricultural crops, vineyards and orchards.
Dissemination: 
Common chickweed reproduces by seed or by stems rooting at inter-nodes. One plant can produce many generations of seedlings during a season.
Of interest: 
Common chickweed is sometimes confused with mouseear chickweed-Cerastium vulgatum and scarlet pimpernel-Anagallis arvensis. It is edible and is used in salads and as a food for caged domestic birds.
Prostrate habit of common chickweed. James Altland, USDA-ARS
Opposite foliage arrangement. James Altland, USDA-ARS
Close-up of flower. James Altland, USDA-ARS
Stem of common chickweed. James Altland, USDA-ARS