PLANTS: Annual or perennial herbs, shrubs, vines or trees. LEAVES: entire, generally opposite; sometimes appearing whorled because the stipules are leaf-like. INFLORESCENCE: cymose, or paniculate, flowers in heads, clusters, or solitary. FLOWERS: actinomorphic, perfect, sometimes functionally imperfect; sepals 4-5(-6), united, the lobes sometimes reduced or obsolete; petals (3-)4-5, united; stamens epipetalous, alternate with corolla lobes; ovary inferior, 2-4-loculed, the style 1, sometimes bifid. FRUIT: of 2-4 nutlets, or berries, drupes, or capsules. NOTES: Ca. 500 genera, ca. 6000 spp.; world-wide, especially tropical. Many cultivated, including Coffea, (coffee), Cinchona, (quinine), and many ornamentals. NOTES: Ca. 500 genera, ca. 6000 spp.; world-wide, especially tropical. Many cultivated, including Coffea, (coffee), Cinchona, (quinine), and many ornamentals. REFERENCES: Dempster, Lauramay T. 1995. Rubiaceae. J. Ariz. - Nev. Sci. 29(l): 29.