The families of flowering plants

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L. Watson and M. J. Dallwitz

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.

Axial (stem, wood) anatomy. Secondary thickening developing from a conventional cambial ring.

The vessel end-walls scalariform. The vessels without vestured pits. The axial xylem with tracheids.

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 ultimate inflorescence units 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, phytochemistry. Saponins/sapogenins absent.

Geography, cytology. Chile. N = 16.

Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Malviflorae; Euphorbiales (?). Cronquist’s Subclass Rosidae; Celastrales. APG 3 core angiosperms; core eudicot; Superorder Berberidopsanae; Order Berberidopsidales.

Species 1. Genera 1; only genus, Aextoxicon.

Illustrations. • Aextoxicum punctatum (Hook. Icones, 1837). • Technical details.

The descriptions are offered for casual browsing only. We strongly advise against extracting comparative information from them. 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 or lacking specified attributes, distributions of character states within any set of taxa, geographical distribution, genera included in each family, and classifications (Dahlgren; Dahlgren, Clifford, and Yeo; Cronquist; APG).

Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 1992 onwards. The families of flowering plants: descriptions, illustrations, identification, and information retrieval. Version: 16th May 2016.’.