The families of flowering plants


L. Watson and M. J. Dallwitz

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).


The vessels without vestured pits. ‘Included’ phloem absent.

Reproductive type, pollination. Fertile flowers hermaphrodite. 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, phytochemistry. Iridoids detected (S.R. Jensen, unpublished); ‘Route I’ type.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.

General remarks. Seemingly aberrant Rubiaceae, differing according to the present compilation only in the stipules without colleters and the multiple fruits (and unconvincingly in homostyly and vessels without vestured pits).

Illustrations. • Adina globiflora: Bot. Reg. 895, 1825. • Sketches.

