The genera of Leguminosae-Caesalpinioideae & Swartzieae
Cynometra p.p. (C. afzelii Oliv. and C. laxiflora Benth.)
Type species: A. laxiflora (Benth.) Mackinder & Wieringa.
Habit and leaf form. Trees (to 25 m), or shrubs (without imbricate bud scales); unarmed.
Phyllotaxy distichous, or spiral (?). The leaves compound; pinnate, or bifoliolate; paripinnate (the rachis sometimes winged). The leaflets few per leaf (1- or 2-jugate); opposite or sub-opposite; petiolulate, or sessile to sub-sessile; without noticeably twisted petiolules; symmetrical or nearly so; of pinnate leaves, with a predominant midrib (the venation pinnate); without a continuous marginal nerve. Stipules absent or early caducous or very inconspicuous in mature leaves; connate (fused, the bases not auriculate). Stipels absent.
Inflorescence and floral morphology. The inflorescences lax, axillary and terminal; unbranched; simple racemes. The flowers not distichous. Bracts absent at anthesis, or absent at anthesis to persistent beyond anthesis. Bracteoles present; petaloid, relatively large and enclosing the flower buds (inserted at the base of the calyx tube); persistent beyond anthesis; not valvate; free.
The flowers small; hermaphrodite; not pentamerous throughout; departing from pentamery in the calyx; coloured. Floral tube length relative to total hypanthium + calyx length about 0.25. Hypanthium present; saucer-shaped to cupular (or funnel-shaped). The perianth comprising distinct calyx and corolla. Calyx 4; covering the rest of the flower in bud; not Swartzieae type; slightly longer than the hypanthium, polysepalous; more or less regular; members imbricate. Corolla present; very irregular; 5 (comprising three large petals and two small ones); including greatly reduced members (the adaxial and lateral petals similar in size and much larger than the reduced adaxial pair); polypetalous. Petals (the large ones) clawed; imbricate; imbricate-ascending; pale to lemon yellow (initially), or red (later). Disk absent. The androecium comprising 10 members; members all free of one another; members all more or less equal in length; comprising only fertile stamens. Fertile stamens 10. Anthers attached well above the base of the connective; dehiscing longitudinally. Ovary stipitate; eccentric, with the stipe adnate. Stigma small, but dilated. Ovules few (2).
Fruit, seed and seedling. Fruit a two-valved pod (compressed, glabrous, obliquely triangular, explosively dehiscent, with 1–2 seeds); not internally septate; valves twisting and enrolling during dehiscence; not becoming woody. The mature valves with conspicuous, prominent, raised venation; conspicuous venation reticulate, not predominantly longitudinal. Seeds non-endospermic; with a straight or slightly oblique radicle; amyloid-positive. Cotyledons not flat; of Type 4; with a vascular system ramified throughout; epigeal.
Wood anatomy. Wood with septate fibres, or without septate fibres; storied, or not storied; without normal intercellular canals; without traumatic canals. Intervascular pits very small.
Pollen ultrastructure. Tectum reticulate, or striate; rugulose reticulate; interwoven striate. Length of colpi greater than one half pole to pole distance.
Species number and distribution. 2 species (A. afzelii, A. laxiflora). Tropical Africa.
Miscellaneous. Illustrations: • A. afzelii: Mackinder & Wieringa (2013).
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’.