Definition of: rubiaceous

(r′bē·ā′shəs) adjective Bot.
Belonging or pertaining to a large, chiefly tropical family (Rubiaceae) of trees, shrubs, and herbs, the madder family of the order Rubiales, with simple opposite or whorled leaves and perfect, often dimorphous, flowers, including plants yielding coffee, quinine, and ipecac. [<L rubia madder]