The genera of Leguminosae-Caesalpinioideae & Swartzieae
Type species: B. excelsa Pittier (?).
Habit and leaf form. Trees; unarmed.
The leaves compound; pinnate; paripinnate. The leaflets few per leaf; opposite or sub-opposite; petiolulate; without a continuous marginal nerve.
Inflorescence and floral morphology. The inflorescences borne on trunk and branches; subsessile, capitellate heads, covered by the bracts. The flowers not distichous. Bracts tomentellose, persistent beyond anthesis. Bracteoles absent; absent at anthesis.
The flowers showy; hermaphrodite; not pentamerous throughout; departing from pentamery in the corolla and in the androecium, or in the calyx, in the corolla, and in the androecium. Hypanthium present. Calyx 4–5; not Swartzieae type; gamosepalous. Corolla present; more ore less rudimentary. ligulate, 3–4; including greatly reduced members, or without greatly reduced members; polypetalous. The androecium comprising 12–15 members; with united members; comprising only fertile stamens. Fertile stamens 12–15. Anthers attached well above the base of the connective. Ovary stipitate; eccentric, with the stipe adnate.
Fruit, seed and seedling. The mature valves without prominent venation. Seeds with a straight or slightly oblique radicle.
Transverse section of lamina. 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 not seen either adaxially or abaxially. Simple unbranched hairs not seen. No compound or branched eglandular hairs seen. Capitate glands not seen. Expanded and embedded hair-feet absent. Adaxial: Adaxial interveinal epidermal cell walls markedly sinuous in high-focus optical section; conspicuously pitted; medium-thick. Stomata adaxially very rare. Abaxial: Abaxial stomata predominantly paracytic. Abaxial epidermis not papillate. Abaxial interveinal epidermal cell walls markedly sinuous in high-focus optical section; conspicuously pitted in optical section; staining normally with safranin; medium-thick.
Wood anatomy. Intervascular pits very small.
Pollen ultrastructure. Tectum reticulate; verrucose reticulate. Length of colpi greater than one half pole to pole distance.
Species number and distribution. 4 species (B. disepala, B. excelsa, B. macrofoliolata, B. peruviana). Brazil.
Tribe. Detarieae; Amherstieae clade of Bruneau et al. (2008).
Comments. Widely cultivated.
Miscellaneous. Illustrations: • B. excelsa, fruit and seed: Contr. U.S. Nat. Herb. 18 (1916). • B. excelsa, e.m. scanned pollen (Graham & Barker, 1981).
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’.