Alchemilla mollis

No one's going to say anything? Really, no one's going to say it? I mean, I'll say it if no one else will because someone's got to...
All right, fine.
Alchemilla mollis (Lady's Mantle) is a menace of a weed no matter how you look at it. I cannot be rid of it. It devours gardens while my back is turned. I've scratched futile days away clawing at its rhizomes only to find, upon my next visit, it has returned in viral numbers. It seeds itself with a profusion and desperation usually reserved for certain notorious annual weeds. Yet everyone turns a blind eye to these truths, defending A. mollis as though it were a troubled youth who means well, no matter how many schools he burns down. Yes, the foliage is pretty, and it prettily holds dew and raindrops in its leaves, but once you've held a thunderstorms' worth of rain in your Alchemilla leaves alone, the novelty wears off.
Everyone loves this plant at first sight... and second and maybe third sight. Then it flowers and people aren't quite sure how to feel about the sloppy yellow inflorescences which seem to belong to another, quite different plant (who would have guessed this thing belongs to the Rose family). Then it explodes, producing a million seeds which germinate at about 99.9% success rate no matter what the soil or exposure, and people nervously reason that if they liked a plant enough to buy it in the first place, then having a million more for free must surely be a good thing. Then they sit in passive denial for a year or so until one morning they open the front door and can't find a way through the garden because there is no garden anymore... only an uncrossable sea of Alchemilla mollis... and they call Garden Search and Rescue, aka yours truly, who is airlifted in and charged with the unenviable but heroic task of finding safe passage through the sea to rescue them before food and water supplies run out.
Do not fall in love with this plant, no matter how delightfully blue-green the leaves seem at first glance; do not give away your garden and affections for the price of a pretty dew-drop. This Lady's Mantle is ravenous.
There, I said it.