This is not the Mullein Ulysses used against the wiles of Circe. At least it doesn’t seem to be. My best informed guess is that the plant in our backyard is a hybrid between the Hoary Mullein Verbascum pulverulentum and the Dark Mullein Verbascum nigrum. I say this because we have two other mulleins in our backyard that seem to match these parents, and the plant in question doesn’t match anything particularly well but shares characteristics of both.
One of my putative parents has hoary hairy leaves and white hairs on all stamens (perhaps the Hoary Mullein) – these are its flowers. (left)
The other is a smaller plant (right) with hardly hairy leaves and purple hairs on the stamens (perhaps Dark Mullein).
There are other species hereabouts. For example, if only three stamens are hairy and those hairs are white, it might be the Great Mullein Verbascum thapsus. To be honest the whole thing is a bit messy and I have no confidence in my identification of the Hoary Black Mullein.
The Great Mullein, by the way, is a common species throughout Europe and most likely the one associated with Homer’s Ulysses story. It’s also a weed, and a noxious one at that, in many places around the world
Mullein has a multitude of common names and reputed medicinal properties: you can look up this 1931 herbal for both.