There is one very common plant in Oregon which you should watch out for, belladonna. It is a vine with tri-lobed, non-serated leaves, small purple flowers with a yellow stamen and produces small red berries that are poisonous.
Does it look like
THIS.
This web site says they are not
very poisonous, however the
Oregon Poison Control Center says they are quite poisonous. If you have any questions, give them a call. It might be worth noting their contact info as they are a very handy resource.