PIE rdical for "thorn"?

From: alexmoeller@...
Message: 14177
Date: 2002-07-31

we dont have a PIE radical in Pokorny's dictionary or in another
dictionar.
Can we suppose the form *tern for this radical?
We have in german "dorn" in english "thorn" and in romanian "ta:rn" for
instance.
What does speak against it?

Best regards

a. moeller