Where does “três-marias” come from?

três-marias (Portuguese) comes from German Marias, from French mariage, from French marier, from Middle French marier, from Old French marier, from Latin marītō, from Latin marītus, from Latin mās — to measure.

três-marias (Portuguese): the name given to various nictaginaceous climbing plants of the genus Bougainvillea, especially Bougainvillea spectabilis, native to America, cultivated in temperate regions as ornamentals for their large bracts of varying colors, especially violet or pink