Unknown Tree II

Here is the next tree I am having trouble identifying. And infact I thought it was the same as Unknown Tree I, until it flowered. Here is the description:

unidentified wildflower

These tiny little beauties grew in the cooler and dark area under our mobile home. The flowers are approx. 1/2 inch across and they line up a single stem along with leaves.. see both pics. This plant is 2ft high, bloomed in Late July, zone 4. Any ideas?

water, mud, kid and dog

Silly Bandit. Never ending entertainment here.