It is a non-native invasive in California (and I presume in OR and WA too).
Our state agencies are on it:
https://www.cal-ipc.org/plants...
Jepson also clearly shows it is an introduction:
https://ucjeps.berkeley.edu/cg...
And just to reiterate: this plant is really poisonous! Children and pets die from it with grim regularity. Get rid of it if you have either, or it is not native to your area.
