Rubiaceae

Trees, shrubs, lianas or herbs. Leaves simple, crosswise opposite or sometimes whorled. Stipules often sheathing the stem. Inflorescence various. Flowers actinomorphic, 4—5-merous, epigynous, usually hermaphrodite. Sepals 4—6, free or fused, margin sometimes entire. Corolla sympetalous; petals 4—6. Stamens as many as the corollalobes, inserted on the corolla-tube and alternating with the lobes. Ovary inferior, 1—10- but usually 2-locular; style filiform; stigma often bilobed. Epigynic disk mostly present. Ovules 1 to many in each locule. Fruit and seeds various. Endosperm nuclear. About 6000 species in 500 genera of world-wide distribution, most abundant in the tropics.