tall, single purple stem weed?
I have several tall weeds in my yard, that have a reddish purple single stem. The leaves look something like dandelion leaves but thinner. I don't know if I want to pull these things, because they look sort of toxic. They range from 3-4 feet tall, don't have a flower right now, and I've never seen them before. When they were first growing I thought they were dandelions.
Can anyone help identify them? I've been searching the internet to no avail.
I can post a pic if that would be helpful.
Thanks in advance,