My mystery plant turned out to be Caper Spurge. It is a garden escapee on both coasts but I have never noticed it before.
Caper Spurge
Although it has a reputation for repelling moles and voles, it is very toxic to people and pets. I will keep it because it is pretty and evergreen during my tough winter. Maybe it repels deer, rabbit, and even voles and moles. Look, don’t touch.
Caper Spurge 2
Caper Spurge is a biennial, occassionally an annual, but this is my plant’s third year. It is setting a lot of seed, so I may get a colony next year. I have three right now.
Although used historically for several medicinal purposes, and as a poison to kill people, it is no longer recommended. It is said to have anti-tumor properties, and has been effective against acute lymphocytic and granulocytic leukemia, and further studies need to be done.
Caper Spurge is an attractive toxin, do not eat it!
treeseeddreaming 
It has for better or worse found its way to my shores. Always good to know about what might turn up in the garden.
Helen,
I laughed when poisoning someone was it’s number one use.