RUBIACEAE

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            1. SYSTEMATIC POSITION:
            Bentham & Hooker
            Division: Phanerogames (Seed Plants)
                 Class: Dicotyledones
                        Sub-class: Gamopetalae
                               Series: Inferae
                                     Order: Rubiales
                                           Family: Rubiaceae
           
            2. MORPHOLOGICAL CHARACTERS:
            Habit – Mostly shrubs and small trees with some vine, and herb.
            Leaves – Opposite, simple, entire or slightly toothed, stipules interpetiolar, bristle-like or leafy and scarcely distinguishable from leaf.
            Inflorescence – Solitary or in small axillary clusters of cymes, or decussate panicles, or umbels or globose head.
            Flower – Bisexual mostly actinomorphic, epigynous.
            Calyx – Sepals 4 or 5, united.
            Corolla – Petals 4 or 5, united.
            Androecium – Stamens 4 or 5, epipetalous, anthers introse, dithecous.
            Gynoecium – Carpel 1-8, syncarpous, ovary inferior, rarely superior or semi-inferior 2-locular with 1-many ovules in each loculus, style filiform, sometimes bifid or multifid, ovary crowned by a more or less annular fleshy disc.
            Fruit – A capsule, berry or drupe.

            4. COMPARATIVE SYSTEMATIC POSITION AND AFFINITIES:
            Bentham & Hooker have placed this family with Caparifoliaceae in the order Rubiales. However, Hutchinson has placed these two families in the order Asterales. Takhtajan consider the family as related to Loganiaceae and allied families and hence they placed it in the order Gentianales. Thorne also placed it under order Gentianales.
            Affinities of Rubiaceae are controversial. Similar type of alkaloids brings Rubiaceae close to Loganiaceae. But, in Loganiaceae the ovary is superior, while it is inferior in Rubiaceae. In possessing opposite leaves, cymose inflorescence and inferior ovary Rubiaceae comes closer to Caprifoliaceae. However leaves are exstipulate in Caprifiliaceae. In possessing epigynous flowers, cymose inflorescence, epigynous disc and bicarpellate ovary, Rubiaceae comes nearer to Apiaceae and Cornaceae.
            5. ECONOMIC IMPORTANCE:
            The members of this family have both medicinal and ornamental values. Some members are used as beverage.
            1. Coffea Arabica, is used as a beverage which is common in India.
            2. Cinchona officinalis, C. calisaya, C. succirubra, etc. yield a drug called quinine which is used in the treatment of malarial fevers.
            3. A number of plants are grown as ornamentals – Ixora spp., Gardenia spp., etc.
            4. Rubia cordifolia is a die yielding plant.

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