Details matter

[Retrograde]

4. There's a European plant also sometimes called marigold

Calendula officinalis, used in medieval and later England for its edible petals and other useful parts. It's in the same family as Tagetes sp., the Mexican marigold, but they're not that closely related. I've come across Calendula species sold as marigolds in some British seed catalogs, so yes, it is possible to find a type of marigold on the moors - but they wouldn't be the same as what Americans call marigold (and I can attest that Calendula officinalis is very good at taking over, at least in my garden)

But I agree - a misplaced detail, especially when the author brags about how much they researched the book - can drag me right out of the story. A big offender for me was