| # The Families of Angiosperms |

L. Watson and M.J. Dallwitz

### Bonnetiaceae Beauvis

~ Theaceae.

Habit and leaf form. Mostly glabrous trees, or shrubs (mostly of sandy or swampy (including coastal) ground); resinous, or not resinous. Plants non-succulent. Leaves alternate (crowded towards the branch tips); decurrent, very shortly and broadly petiolate to sessile; non-sheathing; simple. Lamina entire; conspicuously asymmetric, or not conspicuously asymmetric; oblanceolate, or obovate; pinnately veined (with closely ascending veins); cross-venulate. Leaves exstipulate. Lamina margins entire.

Leaf anatomy. The leaf lamina dorsiventral. Mucilaginous epidermis present. Stomata present; mainly confined to one surface (abaxial); paracytic. Adaxial hypodermis present, or absent. The mesophyll with sclerenchymatous idioblasts, or without sclerenchymatous idioblasts (?).

Axial (stem, wood) anatomy. Young stems with spongy internodes. Secretory cavities absent. Cork cambium present; initially superficial. Primary vascular tissues in a cylinder, without separate bundles. Internal phloem absent. Cortical bundles absent. Medullary bundles absent. Secondary thickening developing from a conventional cambial ring. Primary medullary rays narrow.

The wood diffuse porous. The vessels small to medium; exclusively solitary. The vessel end-walls slightly oblique; mostly simple. The vessels without vestured pits; without spiral thickening. The axial xylem with tracheids; with vasicentric tracheids; with fibre tracheids; without septate fibres. The fibres without spiral thickening. The parenchyma apotracheal and paratracheal. The secondary phloem not stratified. ‘Included’ phloem absent. The wood not storied. Tyloses present (sometimes abundant), or absent.

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

Inflorescence, floral, fruit and seed morphology. Flowers solitary, or aggregated in ‘inflorescences’; when aggregated, in racemes, or in panicles. Inflorescences terminal; terminal panicles, false umbels or racemes. Flowers conspicuously bracteate; (bi-) bracteolate; medium-sized to large; fragrant. Free hypanthium absent. Hypogynous disk absent.

Perianth with distinct calyx and corolla; 10; 2 whorled; isomerous. Calyx 5; 1 whorled; polysepalous (the sepals unequal); persistent, or not persistent; imbricate. Corolla 5; 1 whorled; polypetalous; contorted; red.

Androecium 40–100 (‘many’). Androecial members branched (with trunk bundles); maturing centrifugally; free of the perianth, or adnate (to the bases of the petals); free of one another, or coherent; when coherent, 1 adelphous (slightly connate basally), or 5 adelphous (bundled, in Archytaea and Ploiarium). The androecial bundles when present, opposite the corolla members (and adnate to them). Androecium exclusively of fertile stamens. Stamens 40–100 (‘many’, deciduous or persistent); polystemonous; when bundled, alternisepalous. Anthers small, versatile; dehiscing via longitudinal slits; tetrasporangiate. Pollen grains aperturate; 3 aperturate; colporate.

Gynoecium 3 carpelled, or 5 carpelled. Carpels reduced in number relative to the perianth, or isomerous with the perianth. The pistil 3 celled, or 5 celled. Gynoecium syncarpous; synovarious, or synstylovarious, or eu-syncarpous; superior. Ovary 3 locular, or 5 locular; sessile. Gynoecium stylate. Styles 1, or 3, or 5; when not wholly united, free to partially joined; apical. Stigmas 3, or 5. Placentation axile. Ovules 30–50 per locule (‘many’); pendulous to horizontal (usually ‘spreading’); non-arillate; embryology not recorded.

Fruit non-fleshy; dehiscent; a capsule. Capsules septicidal (usually with the columella persistent). Fruit many seeded. Seeds endospermic, or non-endospermic. Embryo well differentiated. Cotyledons 2. Embryo straight.

Geography, cytology. Paleotropical and Neotropical. Tropical. Southeast Asia, Malesia, tropical America.

Taxonomy. Subclass Dicotyledonae; Crassinucelli (seemingly). Dahlgren’s Superorder Theiflorae; Theales. Cronquist’s Subclass Dilleniidae; Theales. APG III core angiosperms; core eudicot; Superorder Rosanae; fabid. APG IV Order Malpighiales.

Species 32. Genera 4; Archytaea, Bonnetia, Neblinaria, Ploiarium.

General remarks. Maguire (1972) refered to Bonnetiaceae several genera (e.g. Kielmeyera, Marila, Caraipa) referred by Airy Shaw and here to Guttiferae.

Illustrations. • Archytaea triflora: Martius, Nova Gen. et Spec. Pl. Brasiliensium 1 (1824). • Bonnetia anceps: Martius, Nova Gen. et Spec. Pl. Brasiliensium 1 (1824). • Bonnetia paniculata (Hutchinson).

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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