| # The Families of Angiosperms |

L. Watson and M.J. Dallwitz

### Humbertiaceae Pichon

~ Convolvulaceae.

Habit and leaf form. Tall trees. Leaves alternate; leathery; simple. Lamina entire. Leaves exstipulate. Lamina margins entire.

Leaf anatomy. The leaf lamina dorsiventral. Stomata present; paracytic. Lamina without secretory cavities.

Axial (stem, wood) anatomy. Secretory cavities absent. Internal phloem perhaps present (?cf. Convolvulaceae). Secondary thickening developing from a conventional cambial ring, or anomalous (?).

‘Included’ phloem absent.

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

Inflorescence, floral, fruit and seed morphology. Flowers solitary; axillary; (bi-) bracteolate; very irregular; zygomorphic; 5 merous. Floral receptacle developing a gynophore (this short and thick). Free hypanthium absent. Hypogynous disk absent.

Perianth with distinct calyx and corolla; 10; 2 whorled; isomerous. Calyx 5; 1 whorled; polysepalous; persistent; much imbricate. Corolla 5; 1 whorled; gamopetalous; contorted (and unilaterally induplicate); campanulate (with short lobes, these and the tube densely adpressed-ferrugineous-pubescent externally); unequal but not bilabiate.

Androecium 5. Androecial members adnate; free of one another; 1 whorled. Androecium exclusively of fertile stamens. Stamens 5; inserted near the base of the corolla tube; isomerous with the perianth; oppositisepalous; alternating with the corolla members; inflexed in bud (declinate at anthesis); filantherous (the anthers long exserted). Anthers basifixed; non-versatile; dehiscing via longitudinal slits; introrse.

Gynoecium 2 carpelled. Carpels reduced in number relative to the perianth. The pistil 2 celled. Gynoecium syncarpous; eu-syncarpous; superior. Ovary 2 locular; stipitate. Gynoecium stylate. Styles 1 (deflexed in bud); apical. Stigmas 1; small, truncate. Placentation axile. Ovules 30–50 per locule (‘many’); anatropous.

Fruit non-fleshy; indehiscent (crustaceous); 4 seeded.

Geography, cytology. Paleotropical. Tropical. Madagascar.

Taxonomy. Subclass Dicotyledonae; Tenuinucelli. Dahlgren’s Superorder Solaniflorae; Solanales. Cronquist’s Subclass Asteridae; Solanales. APG III core angiosperms; core eudicot; Superorder Asteranae; lamiid. APG IV Order Solanales (as a synonym of Convolvulaceae).

Species 1 (Humbertia madagascariensis). Genera 1; only genus, Humbertia.

General remarks. This description is inadequate, but offers several fairly conspicuous differences from Convolvulaceae sensu stricto (q.v.).

Illustrations. • Humbertia madagascariensis: Th. Deroin, in Fl. de Madagascar (2001).

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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