Thanks for the quick response and the link. Such an intriguing common name.

It looks a bit different from the C lutetiana I see here. The furrowed leaves for instance. I believe there are other Circaea species/sub species in N america. Could it be one of those do you think Carol?

It could be x intermedia, alpina.... from the USDA database. click on subordinate taxa

https://plants.usda.gov/core/profile?symbol=CIRCA

Thanks for the link. Based on looking at it and researching further, I think it’s C. lutetiana. X intermedia alpina is much more compact than the plant in my friend’s garden and the configuration of the flowers is different. https://www.florafinder.org/Species/Circaea_lutetiana.php My impression is that C. lutetiana isn’t a nuisance which is nice.

It would be a weed in my garden. The seeds stick to clothing. It has little ornamental value.

C lutetiana is fine in its natural habitat but it's definitely a weed on my allotment. It has creeping white roots which spread and break off when you pull a stem. Not to mention the sticky seeds.

I kind of like it. That said, I think it would be a weed in virtually anyone’s garden, but it doesn’t seem to be as problematic in uncultivated areas as garlic mustard or Japanese stilt grass, for example, are. It popped up and my friend was curious to see what it was. Her yard borders a nature preserve so seeds may have hitched a ride on a chipmunk or something.

In a natural area it wouldn't be a problem since it's not an alien invasive like your other two examples.