Solanaceae, or the Nightshades, are a family of flowering plants. It's a pretty broad category of plants, including things like tomatoes, eggplant, and potatoes, but also tobacco, goji berries, and a bunch of different decorative plants.

Some nightshades are poisonous (like the aptly named Deadly Nightshade - Atropa belladonna.) Some nightshades will make you hallucinate. Some have medicinal properties.