Flower appeared in several places (Chicago, Illinois, USA). Any ideas? Weed? The roots seem to spread out rather than down. Two flower colors appeared of different flowers, dark pink and light pink. Leaves are elliptical with teeth, medium-light green, stem is lighter. Flowers appear in clusters and pop up in sunny and part shade areas.
Impatiens glandulifera. Definitely weed, and very successful one at that. Pretty, though. Impatiens glandulifera, Ornamental Jewelweed – Invasive Species