The Families of Flowering Plants
The Families of Flowering Plants |
|
~ Rubiaceae
Habit and leaf form. Trees and shrubs, or lianas. Climbing (sometimes), or self supporting. Mesophytic. Leaves opposite, or whorled; simple. Lamina entire. Leaves stipulate. Stipules interpetiolar, or intrapetiolar (rarely); caducous (usually), or persistent (when intrapetiolar). Lamina margins entire.
Leaf anatomy. Minor leaf veins without phloem transfer cells (1 genus).
Stem anatomy. Internal phloem absent. Secondary thickening developing from a conventional cambial ring. ‘Included’ phloem absent. Vessels without vestured pits.
Reproductive type, pollination. Plants hermaphrodite; homostylous.
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in heads. Inflorescences terminal, or axillary; in dense, globose heads. Flowers bracteate, or ebracteate; regular; 4–5 merous; cyclic; tetracyclic. Free hypanthium absent.
Perianth with distinct calyx and corolla; 8, or 10; 2 whorled; isomerous. Calyx 4, or 5; 1 whorled; gamosepalous; regular; persistent, or not persistent; imbricate, or valvate. Corolla 4, or 5; 1 whorled (usually), or 12 whorled; gamopetalous. Corolla lobes markedly shorter than the tube (the tube long, the lobes short). Corolla imbricate, or valvate; funnel-shaped; regular.
Androecium 4, or 5. Androecial members adnate; all equal; free of one another; 1 whorled. Androecium exclusively of fertile stamens. Stamens 4, or 5; inserted in the throat of the corolla tube; isomerous with the perianth; oppositisepalous; alternating with the corolla members. Anthers dehiscing via longitudinal slits.
Gynoecium 2 carpelled. Carpels reduced in number relative to the perianth. The pistil 2 celled. Gynoecium syncarpous; synstylovarious to eu-syncarpous; inferior. Ovary 2 locular. Gynoecium transverse (?). Styles 1; apical. Stigmas 1; 1–2 lobed. Placentation axile, or apical. Ovules 1–50 per locule (i.e. to ‘many’); pendulous (‘or attached to the middle of the septum’); non-arillate.
Fruit fleshy, or non-fleshy; dehiscent (usually), or indehiscent; a capsule. Gynoecia of adjoining flowers more or less combining to form a multiple fruit. The multiple fruits coalescing (fleshy), or not coalescing (dry). Seeds endospermic. Endosperm oily. Seeds minute (usually flattened).
Physiology, biochemistry. Iridoids detected (S.R. Jensen, unpublished); ‘Route I’ type. Aluminium accumulation demonstrated.
Geography, cytology. Tropical. Pantropical?.
Taxonomy. Subclass Dicotyledonae; Tenuinucelli. Dahlgren’s Superorder Gentianiflorae; Gentianales. Cronquist’s Subclass Asteridae; Rubiales. APG 3 core angiosperms; core eudicot; Superorder Asteranae; lamiid; Order Gentianales (as a synonym of Rubiaceae).
Species 200. Genera about 10; Adina, Breonia (inc. Platanocephalus, Anthocephalus), Cephalanthus, Mitragyna (inc. Stephegyne), Nauclea, Neonauclea, Sarcocephalus, Uncaria.
Illustrations. • Adina globiflora: Bot. Reg. 895, 1825. • Sketches.
This description is offered for casual browsing only. We strongly advise against extracting comparative information from it. This is much more easily achieved using the interactive key, which allows access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting specified attributes, summaries of attributes within groups of taxa, geographical distribution, genera included in each family, classifications (Dahlgren; Dahlgren, Clifford, and Yeo; Cronquist; APG), and notes on the APG classification.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 1992 onwards. The families of flowering plants: descriptions, illustrations, identification, and information retrieval. Version: 4th March 2011. http://delta-intkey.com’.
