Rubiaceae
Rubiaceae Juss. is an accepted family in the order Gentianales according to the Angiosperm Phylogeny Group IV (APG IV) and is recognized by Plants of the World Online (POWO) and World Flora Online (WFO). It is the fourth-largest family of angiosperms, comprising approximately 620–630 genera and 13,500–14,000 species distributed worldwide. Molecular phylogenetic studies recognize three major subfamilies—Rubioideae, Cinchonoideae, and Ixoroideae—which have greatly refined the classification of this highly diverse family. Members are characterized by opposite leaves with interpetiolar stipules, epigynous flowers, an inferior ovary, and fruits that may be capsules, berries, drupes, or schizocarps.
Key characteristics
- Herbs, shrubs, trees, or climbers
- Leaves opposite or whorled
- Interpetiolar stipules present
- Flowers epigynous and actinomorphic
- Corolla tubular or salverform
- Stamens epipetalous
- Ovary inferior
- Fruits berries, capsules, drupes, or schizocarps
Distribution
Rubiaceae has a cosmopolitan distribution, although nearly 75% of species occur in tropical and subtropical forests. Major centres of diversity include Tropical South America, Central America, Tropical Africa, Madagascar, Southeast Asia, Indo-Malayan Region. Species occupy habitats ranging from Tropical rainforests, Montane forests, Grasslands, Wetlands, Deserts, Alpine meadows. In Pakistan, Rubiaceae occurs throughout, Himalayan forests, Salt Range, Potohar Plateau. Members occur in Forest understories, Grasslands, Agricultural fields, Stream banks, Mountain slopes, Dry scrublands. Representative Pakistani genera include Galium, Rubia, Oldenlandia, Hedyotis, Kohautia, Leptodermis, Callipeltis.