From the experts:
Marigold, once found almost exclusively in English novels and aristocratic nurseries, is beginning to be talked about and considered here; it does have a sunny, golden feel. The marigold was the symbol of the Virgin Mary.
Marigold appears in several children's book titles, such as Magic for Marigold, Once Upon a Marigold and Marigold in Godmother's House, and in the adult Quartet in Autumn by Barbara Pym. On the TV show 1600 Penn, Marigold was the President's young daughter.