"Of the nature of an acanthus; (in later use) specifically belonging to or characteristic of the family Acanthaceae, comprising chiefly tropical shrubs and vines and having the genus Acanthus as the type genus", Mid 18th cent.; earliest use found in Ephraim Chambers (?1680–1740), encyclopaedist. From post-classical Latin acanthaceus + -ous.[acanthaceous etymology, acanthaceous origin, 英语词源]