Nightshade with 4 white petals?
I've been trying to identify this plant which has been spreading quickly into my property in a shady area. It certainly looks like some member of the nightshade family but I haven't been able to figure out which one. The plants are about 4 to 12" high with purplish stems, no visible hairs, unpleasant odor. The flowers look like American Nightshade with white petals and a protruding yellow centre but the American nightshade (that I've seen online) always has five petals and this has four (somewhat irregularly shaped). Any guesses?