One or other of the wild lettuce family, perhaps Latuca canadensis, it's classified as weed and grows in disturbed soil. So I have a small forest of these growing where I have leftover excavated soil from where I redid the drainage at my house.
These pretty little flowers only open if the sun shines and quickly close if it becomes cloudy. The bees love visiting and digging around in the flowers, the pollen is contained in the little dark strands
Looking at the powder puff seed heads and large numbers of aphids - autumn is here and the heat and dry weather brings the aphids out
Although wild lettuce plants are used medicinally and they have a white milky sap, they aren't members of the milkweed family. It seems that wild lettuce has pain-relieving properties.