The genera of Leguminosae-Caesalpinioideae & Swartzieae
Type species: V. americana Aubl.
Habit and leaf form. Trees; unarmed.
Phyllotaxy spiral. The leaves compound; pinnate (the petioles glandular, at least beneath the proximal leaflets); imparipinnate; with adaxially grooved rachides. The leaflets few per leaf (2–4 pairs); glabrous, opposite or sub-opposite; symmetrical or nearly so; pinnately veined, with a predominant midrib. Stipules absent or early caducous or very inconspicuous in mature leaves (caducous); membranous. Stipels absent.
Inflorescence and floral morphology. The inflorescences terminal; branched; of racemose units; panicles. Bracteoles present; small, not enclosing the flower buds; absent at anthesis.
The flowers small; hermaphrodite; actinomorphic; pentamerous; coloured. Hypanthium present; cupular. Calyx 5; not Swartzieae type; polysepalous; more or less regular; members imbricate. Corolla present; regular; 5; without greatly reduced members; polypetalous. Petals slightly exceeding the sepals, equal, rounded, broadly subspathulate imbricate; imbricate-ascending; yellow. Disk obscurely present and conspicuous to absent (lining the concave receptacle, thin and 10-crenate). The androecium comprising 10 members; not declinate; members all free of one another (the filaments basally dilated); members all more or less equal in length; comprising only fertile stamens. Fertile stamens 10. Anthers subsagittate, linear; dehiscing introrsely. Ovary shortly stipitate; free. Stigma small, not dilated (on the short style). Ovules few, or solitary (1–2(-4?)).
Fruit, seed and seedling. Fruit asymmetrically obovoid-pyriform, 1(-3?) seeded, a follicle; without markedly twisting or enrolling valves. The mature valves thick, smooth, without prominent venation. Seeds non-endospermic; with a straight or slightly oblique radicle.
Transverse section of lamina. Leaves without conspicuous phloem transfer cells in the minor veins. Druses absent from the mesophyll. Mesophyll secretory cavities absent. Adaxial hypodermis absent. Leaf girders common (the veins transcurrent). Laminae dorsiventral. Mesophyll without unaligned fibres or sclereids. Minor veins mainly with abundant accompanying fibres.
Leaf lamina epidermes. Epidermal crystals present; prisms. Simple unbranched hairs common; scabrid. Compound or branched eglandular hairs present. Capitate glands not seen. Hooked hairs not seen. Cassieae-type leaf pseudo-glands not seen. Expanded and embedded hair-feet absent. Adaxial: Adaxial interveinal epidermal cell walls markedly sinuous in high-focus optical section; not conspicuously pitted; medium-thick. Stomata adaxially very rare. Abaxial: Abaxial stomata predominantly paracytic. Abaxial epidermis papillate interveinally; with papillae over-arching the stomata. Abaxial interveinal epidermal cell walls markedly sinuous in high-focus optical section; not conspicuously pitted in optical section; staining normally with safranin; thick.
Wood anatomy. Wood without septate fibres; not storied; without normal intercellular canals; without traumatic canals. Intervascular pits very small.
Species number and distribution. 3 species (V. americana, V. macropetala and V. pallidior). Tropical America.
Miscellaneous. Illustrations: • V. americana: Baillon, Histoire des Plantes 2 (1870).
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, and classification. See also Guidelines for using data taken from Web publications.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 1993 onwards. The genera of Leguminosae-Caesalpinioideae and Swartzieae: descriptions, illustrations, identification, and information retrieval. In English and French. Version: 22nd March 2017. delta-intkey.com/caes’.