Naucleaceae (DC.) Wernh.
~ 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 Iridoids detected (S.R. Jensen, unpublished); ‘Route I’ type.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 (1998) Eudicot; core Eudicot; Asterid; Euasterid I; 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. • crude sketches.
Cite this publication as: ‘L. Watson and M. J. Dallwitz (1992 onwards). The Families of Flowering Plants: Descriptions, Illustrations, Identification, and Information Retrieval. Version: 14th December 2000. http://biodiversity.uno.edu/delta/’. Dallwitz (1980), Dallwitz, Paine and Zurcher (1993, 1995, 2000), and Watson and Dallwitz (1991) should also be cited (see References).
