The genera of Leguminosae-Caesalpinioideae & Swartzieae
Type species: B. floribunda Spruce ex Benth.
Habit and leaf form. Trees; unarmed.
Phyllotaxy spiral. The leaves compound; pinnate; imparipinnate; with adaxially grooved rachides. The leaflets opposite or sub-opposite; without noticeably twisted petiolules; symmetrical or nearly so; pinntely veined, with a predominant midrib. Stipules present, persistent and conspicuous in mature leaves; membranous. Stipels absent.
Inflorescence and floral morphology. The inflorescences terminal; branched; of racemose units; panicles. The flowers not distichous. Bracts absent at anthesis. Bracteoles present; small, not enclosing the flower buds; absent at anthesis.
The flowers hermaphrodite; pentamerous; coloured. Floral tube length relative to total hypanthium + calyx length about 0.25. Hypanthium present; shortly cupular (filled by the disc). Calyx 5; covering the rest of the flower in bud; polysepalous; members imbricate. Corolla present; regular; 5; without greatly reduced members; polypetalous. Petals imbricate; imbricate-ascending; yellow. Disk present and conspicuous (filling the hypanthium). The androecium comprising 10 members; members all free of one another; comprising only fertile stamens. Fertile stamens 10. Anthers attached well above the base of the connective; dehiscing introrsely. Ovary stipitate; free. Stigma small, not dilated. Ovules few.
Fruit, seed and seedling. Fruit a follicle; curved; without markedly twisting or enrolling valves; becoming woody. Seeds endospermic; not arillate (pale red, shiny); with a straight or slightly oblique radicle; amyloid-negative.
Transverse section of lamina. Leaves without conspicuous phloem transfer cells in the minor veins. Druses absent from the mesophyll. Mesophyll secretory cavities (gland-dots) common; without a lining of epithelium. Adaxial hypodermis absent. Leaf girders absent. Laminae dorsiventral. Mesophyll without unaligned fibres or sclereids. Minor veins mainly with abundant accompanying fibres.
Leaf lamina epidermes. Epidermal crystals not seen either adaxially or abaxially. Simple unbranched hairs common; smooth. 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 straight in optical section; not conspicuously pitted; medium-thick. Stomata adaxially very rare. Abaxial: Abaxial stomata predominantly paracytic. Abaxial epidermis not papillate. Abaxial interveinal epidermal cell walls straight, or gently undulating; not conspicuously pitted in optical section; staining normally with safranin; thin.
Wood anatomy. Wood with septate fibres; not storied.
Pollen ultrastructure. Tectum punctate; smooth punctate, or puncticulate. Length of colpi greater than one half pole to pole distance (without a margocolpus).
Species number and distribution. 1 species (B. floribunda). Brazil.
Miscellaneous. Illustrations: • B. floribunda: Fl. Brasiliensis 15 (1870). • B. floribunda leaflet: stellate hairs in the abaxial epidermis.
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’.