It's taprooted and will be difficult to transplant.
Common Mullein is on the WA state noxious weed list in certain counties. These plants can produce seeds upwards of 500,000+ seeds per flowering stalk.

Check with your local County Weed Board to see if this one is designated for control...please :D

Vera

Here is a link that might be useful: Common Mullein

Well, its not on the state lists...http://www.nwcb.wa.gov/weed_list/weed_list.htm

But I emailed the county Noxious Weed person. Thanks for the heads up. :)

Hmmm...just got it bounced back to me...seems the address is bad...

Well, since the address is bad, I might as well just leave it where it is anyway. I kinda wanted to just put something in there that needs little to no care but would be useful for something. I could transplant one of the smaller rhubarb crowns, but I'm concerned it would be a target of abuse by people who've been abusing the rhubarb that's already there. I had to build a small wall to keep dog piss off of it.

Say...does anyone know if the burning from urine drives the poison in rhubarb leaves down into the stems? I've heard that the burning from freezes can...

i've transplanted mullein successfully, they need to be very small, and you have to try to get all the taproot up, don't break it. Maybe just quietly toss some nasturtium seeds or something into the empty space.