| # The Families of Angiosperms |

L. Watson and M.J. Dallwitz

### Aitoniaceae Harv. & Sond.

~ Meliaceae, Loganiaceae.

Habit and leaf form. Small trees, or shrubs (much branched, rigid, the twigs angular, puberulous). Leaves alternate; subsessile; non-sheathing; without marked odour; simple. Lamina entire; one-veined (linear-oblong). Leaves exstipulate.

Leaf anatomy. The leaf lamina dorsiventral. Stomata present; anomocytic.

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

The axial xylem with fibre tracheids; including septate fibres (?).

Reproductive type, pollination. Unisexual flowers absent. Plants hermaphrodite.

Inflorescence, floral, fruit and seed morphology. Flowers solitary; axillary; somewhat irregular; 4 merous. Hypogynous disk present; annular (cupular, fleshy, crenate).

Perianth with distinct calyx and corolla; 8; 2 whorled; isomerous. Calyx 4; 1 whorled; shortly gamosepalous. Calyx lobes markedly longer than the tube. Degree of gamosepaly (maximum length joined/total calyx length) 0.2 (or less). Calyx slightly imbricate. Corolla 4; 1 whorled; polypetalous (the petals large); imbricate; purple.

Androecium 8. Androecial members coherent; 1 adelphous (filaments shortly connate); 1 whorled. Androecium exclusively of fertile stamens. Stamens 8; diplostemonous; both alternating with and opposite the corolla members. Anthers introrse.

Gynoecium 4 carpelled. The pistil 4 celled. Gynoecium syncarpous; eu-syncarpous; superior. Ovary 4 locular. Styles 1 (filiform). Stigmas 1; punctiform. Placentation axile. Ovules 2 per locule; amphitropous.

Fruit non-fleshy; dehiscent; a capsule. Capsules loculicidal. Dispersal unit the seed. Seeds non-endospermic. Embryo curved.

Physiology, phytochemistry. Sugars transported as sugar alcohols + oligosaccharides + sucrose.

Geography, cytology. South Africa.

Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Rutiflorae; Sapindales. Cronquist’s Subclass Rosidae; Sapindales. APG III core angiosperms; core eudicot; Superorder Rosanae; malvid. APG IV Order Sapindales (as a synonym of Meliaceae).

Species 1 (Nymania capensis). Genera 1; only genus, Nymania ( syn. Aitonia).

General remarks. Seeming to differ from Meliaceae sensu stricto (q.v.) only in the reduced leaf venation, somewhat irregular flowers and ovule orientation, and convincingly referred to Meliaceae-Turraeae by Pennington and Styles 1975.

Illustrations. • Nymania capensis: Immelman et al., Flora of Southern Africa 18 (1986). • Nymania capensis: Bot. Mag. 173, 1781. • Nymania capensis: Bot. Mag. 173, text.

We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or 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). See also Guidelines for using data taken from Web publications.

Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 1992 onwards. The families of flowering plants: descriptions, illustrations, identification, and information retrieval. Version: 8th June 2026. delta-intkey.com’.

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