I found this while hiking in a canyon. It is apart of what appears to be a vine. It grew widespead in moist soil under partial shade.
Nope, that's a different plant (Atropa belladonna), far more poisonous. Solanum dulcamara (Bittersweet) is only mildly poisonous - eating 2 or 3 berries wouldn't do anything worse than a slightly uncomfortable stomach, you'd have to eat a lot to suffer serious harm.
I can see how it is related to the tomato. When I crushed the fruit it smelled like a tomato and the interior was very similar to the tomato (lots of seeds in a fiberous viscous fluid).
Tomato is Solanum lycopersicum: http://plants.usda.gov/java/profile?symbol=SOLY2 - yep, closely related! People used to think tomatoes were also poisonous, by analogy of its relatives - shows that this is not very safe to predict! And tomato leaves are somewhat poisonous, it is only the fruit that is edibe.
Forgive my faux pas. In future I will leave identification to my betters. ---I thought I WAS when I used the following book as a reference for the Latin name of this plant: Henn, Robert L.: Wildflowers of Ohio (Second Edition); 2008. On page 186, Bittersweet Nightshade (Solanum dulcamara) is depicted. Page 187 gives the description of same, including the following: "Comments. Perennial. Also known as Deadly Nightshade. The berries are poisonous. DO NOT EAT." So...how does one know when the information one is reading is accurate? Should I fire off a hot piece of mail in Mr. Henn's direction?
Solanum dulcamara is a European plant; unfortunately, there is a lot of erroneous information about European plants on your side of the Atlantic. Tip: look for sources of information written by people for whom the plant is a familiar native species, rather than a less familiar exotic. Some Solanum dulcamara information: http://ip30.eti.uva.nl/BIS/flora.php?selected=beschrijving&menuentry=soorten&id=3370 Some Atropa belladonna information: http://ip30.eti.uva.nl/BIS/flora.php?selected=beschrijving&menuentry=soorten&id=3351
