American nightshade.

Working outside this afternoon, doing nothing of particular import except enjoying the fresh air, I was easily distracted when V2 happened by and flushed a grey fox out from a clump of blackberries, adjacent to the Pinot grigio vines, where it was apparently having an afternoon nap.  Always ready to indulge my little terrier mix in any canine-caper she chooses, I joined in hot pursuit of the fox across the creek, behind an oak tree, where it disappeared into another clump of blackberries.  Oh well.  It was then that I spotted a couple of nightshade plants growing at my feet. 
The American nightshade (Solanum americanum) reappears in the same spot beside the creek, next to the pokeweed, every year.  The nightshade is a rather winsome little plant; it's flowers are very pretty; it's immature berries are very shiny and green; it's mature berries are even shinier and black.  These plants can be toxic to animals and humans when ingested as they contain glycoalkaloids, including solanine which can also be found in sprouting potatoes.  However, the degree of toxicity varies depending upon plant population, plant maturity and environmental conditions.  And whether or not a certain little black and white dog's belly is full because she, perhaps, already dined upon a certain Mr. Basil Brush.  Boom! Boom!