An order of flowering plants, division Magnoliophyta (Angiospermae), in the subclass Asteridae of the class Magnoliopsida (dicotyledons). The order consists of the large family Rubiaceae, with about 6500 species and the family Theligoniaceae with only 3 species. The Rubiales are marked by their inferior ovary; regular or nearly regular corolla with the petals grown together by their margins; stamens (equal in number to the petals) which are attached to the corolla tube alternate with the lobes; and opposite leaves with interpetiolar stipules or whorled leaves without stipules. The most familiar species of temperate regions are herbs with whorled leaves, such as madder (Rubia tinctorium, the traditional source of red dye), but opposite-leaved tropical shrubs such as Coffea (the source of coffee) are more typical of the group.