The national flower is the mugunghwa, whose common name in English is, for some reason, Rose of Sharon (which fails to sound Korean at all, a problem I have had for ages when trying to write about it in English-language fiction).

Funnily enough, my papaw brought home a Rose of Sharon from Korea when he was there in the 50's. (Yes indeedy, he smuggled a plant to the US. It and it's descendants have been in our yards since.)