No, these aren't tomatoes. They're related to tomatoes, but don't eat them. They're poisonous.
These are the fruits of Bittersweet Nightshade (Solanum dulcamara), a common weed in North America that's native to Europe and Asia. Click on the photo to see its flowers.
Until I did the research for this blog, I called this plant Deadly Nightshade but that's the common name for a completely different and far more deadly plant, Atropa Belladonna. Belladonna is so poisonous that 2-5 of its deep blue berries can kill a child, 10-20 berries or a single leaf can kill an adult. In Ancient Rome the aristrocracy found it quite effective for killing their rivals.
Both plants are in the Nightshade family (Solanaceae) which includes a wide variety of edible and poisonous species. The edible plants are so tasty that humans went to the trouble of cultivating them: potatoes, tomatoes, eggplants, chili peppers and paprika. The toxic plants are beautiful but dangerous: Deadly Nightshade, Bittersweet Nightshade, Mandrake and Jimson Weed (Datura), to name a few.
Somewhere in humanity's past, people had to figure out which plants were good to eat and which weren't. What a risky business! I'm glad that job is done and we're able to pass on the knowledge.
Meanwhile, don't worry that you'll mistake these berries for tomatoes. Bittersweet Nightshade berries are tiny and the plant smells bad.
(photos by Chuck Tague)