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The genera of Leguminosae-Caesalpinioideae & Swartzieae

L. Watson and M.J. Dallwitz

Bocoa Aubl.

~ Swartzia.

Including Trischidium Tul.

Type species: B. prouacensis Aubl.

Habit and leaf form. Trees (to 30 m), or shrubs (the wood and leaves foetid); unarmed.

The leaves compound, or ostensibly simple; when simple, pinnately veined with a predominant midrib; when unifoliolate, pinnate; imparipinnate. The leaflets few per leaf (1–9, entire); opposite or sub-opposite (often), or alternate; petiolulate; without noticeably twisted petiolules. Stipules absent or early caducous or very inconspicuous in mature leaves, or present, persistent and conspicuous in mature leaves (to 5 mm long); membranous. Stipels absent.

Inflorescence and floral morphology. The inflorescences on older branches, rarely axillary; unbranched, or branched; when branched, of racemose units; simple racemes, or panicles. Bracts absent at anthesis, or persistent beyond anthesis (about 1 mm long). Bracteoles absent; absent at anthesis.

The flowers hermaphrodite; not pentamerous throughout; departing from pentamery in the calyx, in the corolla, and in the androecium; white or green. Hypanthium absent, the androecium hypogynous. The perianth comprising distinct calyx and corolla, or exclusively sepaline. Calyx 2–4; covering the rest of the flower in bud; Swartzieae type (closed before flowering, splitting more or less irregularly into valvate lobes or teeth); gamosepalous, or polysepalous (the segments free or remaining united below); more or less regular, or markedly irregular; members not imbricate. Corolla present, or absent; when present, very irregular; when present, 1–2; without greatly reduced members; polypetalous, or monopetalous. Petals when present, clawed; white. Disk absent. The androecium comprising about 7–30 members; members all free of one another; members all more or less equal in length; comprising only fertile stamens. Fertile stamens 7–30. Anthers attached at the base of the connective (oblong, about equalling or shorter than the filaments, versatile); dehiscing longitudinally. Ovary stipitate (gynophore to 2 mm); free. Stigma not dilated (truncate to capitellate). Ovules numerous (10–14, in two rows, but only the one nearest the style maturing).

Fruit, seed and seedling. The mature valves with conspicuous, prominent, raised venation; conspicuous venation reticulate, not predominantly longitudinal. Seeds arillate, or not arillate (usually); with an inflexed radicle.

Wood anatomy. Wood storied; without normal intercellular canals; without traumatic canals.

Pollen ultrastructure. Tectum punctate; rugulose punctate. Length of colpi greater than one half pole to pole distance.

Species number and distribution. 8 species (Trischidium: B. alterna, B. decipiens, B. limae, B. mollis, B. racemulosa. Sensu stricto: B. prouacensis, B. ratteri, B. viridiflora). South America.

Tribe. Papilionoideae-Swartzieae.


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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’.

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