Aextoxicaceae Engl. and Gilg
Habit and leaf form. Large trees. Leaves alternate (to subopposite); spiral; petiolate; non-sheathing; simple. Lamina entire; cross-venulate. Leaves exstipulate. Lamina margins entire.
Leaf anatomy. Hairs present. Complex hairs lepidote.
Stem anatomy. Secondary thickening developing from a conventional cambial ring. Xylem with tracheids. Vessel end-walls scalariform. Vessels without vestured pits.
Reproductive type, pollination. Fertile flowers functionally male, or functionally female. Plants dioecious. Female flowers without staminodes. Gynoecium of male flowers pistillodial, or vestigial.
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in racemes. The terminal inflorescence unit racemose. Inflorescences axillary (lepidote). Bracts (or rather, single bracteoles) calyptrate. Flowers calyptrate; regular; 5 merous; cyclic. Free hypanthium absent. Hypogynous disk present; of separate members (5).
Perianth with distinct calyx and corolla; 10; 2 whorled; isomerous. Calyx 5; 1 whorled; polysepalous; not persistent (deciduous); imbricate. Corolla 5; 1 whorled; polypetalous; imbricate. Petals spathulate, broadly clawed.
Androecium 5. Androecial members free of the perianth; all equal; free of one another; 1 whorled. Androecium exclusively of fertile stamens. Stamens 5; oppositisepalous. Anthers dehiscing via short slits (above); introrse. Pollen grains aperturate; 3 aperturate; colporate.
Gynoecium 2 carpelled. The pistil 2 celled. Gynoecium syncarpous; synovarious to synstylovarious; superior. Ovary 2 locular. Styles 1 (shortly bifid). Stigmas 2. Placentation apical. Ovules 2 per locule (but only one loculus fertile); pendulous; non-arillate; bitegmic; crassinucellate. Outer integument not contributing to the micropyle.
Fruit non-fleshy (small); indehiscent; a drupe. The drupes with one stone (one-seeded). Fruit 1 seeded. Seeds endospermic. Endosperm ruminate. Cotyledons 2 (these flattened, cordate-orbicular).
Physiology, biochemistry. Saponins/sapogenins absent.
Geography, cytology. Chile. N = 16.
Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Malviflorae; Euphorbiales (?). Cronquist’s Subclass Rosidae; Celastrales. APG (1998) Eudicot; core Eudicot; neither Rosid nor Asterid; unassigned at ordinal level. Species 1. Genera 1; only genus, Aextoxicon.
Illustrations. • Technical details.
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).
