The Collaborative International Dictionary of English v.0.48:
Rubiaceous \Ru`bi*a"ceous\, a. [L. rubia madder, fr. rubeus
red.] (Bot.)
Of or pertaining to a very large natural order of plants
(Rubiaceae) named after the madder (Rubia tinctoria), and
including about three hundred and seventy genera and over
four thousand species. Among them are the coffee tree, the
trees yielding peruvian bark and quinine, the madder, the
quaker ladies, and the trees bearing the edible fruits called
genipap and Sierre Leone peach, besides many plants noted for
the beauty or the fragrance of their blossoms.
[1913 Webster]