I just noticed the flower on this plant that’s in one of my veggie beds. Before it bloomed, I thought it was a Tomato that grew from our compost. Now I think it grew from a seed carried from birds that frequent our yard, since I see bird droppings with seeds in them on the Cucumber next to this plant.

Anyone know what this is?

My garden is in the Northern-East San Francisco Bay Area (zone 9A).