The genera of Leguminosae-Caesalpinioideae & Swartzieae
Type species: M. dumaziana Capuron.
Habit and leaf form. Trees (10–25 m tall); without specialized short shoots; unarmed.
Phyllotaxy spiral. The leaves ovate to oblong-ovate, thinly leathery, ostensibly simple (the short petioles inarticulate); with a predominant midrib. Stipules absent or early caducous or very inconspicuous in mature leaves (caducous); triangular, membranous; not connate.
Inflorescence and floral morphology. The inflorescences few flowered, axillary; basally once or twice branched; of racemose units. The flowers not distichous. Bracts subulate, about 2 mm long, absent at anthesis (caducous).
The flowers 2–2.5 cm in diameter; hermaphrodite; actinomorphic to slightly irregular (sub-actinomorphic); not pentamerous throughout; departing from pentamery in the androecium, or in the calyx, in the corolla, and in the androecium; coloured. Hypanthium more or less absent, the androecium hypogynous (the receptacle flat). The perianth comprising distinct calyx and corolla. Calyx present; small, (5–)6; not covering the rest of the flower in bud; polysepalous; more or less regular (the sepals subequal); members imbricate to not imbricate (scarcely imbricate in the bud, and separating early). Corolla present; regular to slightly irregular (the petals subequal); (5–)6; without greatly reduced members; partially gamopetalous to polypetalous (sometimes having pairs of petals partially or completely fused). Petals much larger than the sepals, elliptic, narrowing basally, sessile; imbricate. Disk absent. The androecium comprising 11–12 members; not declinate; members all free of one another; members all more or less equal in length (subequal); comprising only fertile stamens. Fertile stamens 11–12 (isomorphic, the filaments only a little longer than the orange, narrowly oblong anthers). Anthers attached at the base of the connective; dehiscing apically via pores or short slits (via short, transverse slits). Ovary oblong to sigmoid, flat, sessile or subsessile; free. Stigma dilated (capitate on the short style, which scarcely exceeds the anthers). Ovules few (2(-3)).
Fruit, seed and seedling. Fruit a two-valved pod (with papery valves); compressed, obliquely oblong, straight; not internally septate; valves twisting and enrolling during dehiscence (these subcoriaceous); winged longitudinally; narrowly, ventrally 1 winged; not becoming woody. The mature valves with conspicuous, prominent, raised venation; conspicuous venation not predominantly longitudinal. Seeds non-endospermic; not arillate.
Wood anatomy. Wood with vestured pits - a peculiar feature in the context of Caesalpinioideae.
Species number and distribution. 1 species (M. dumaziana). Madagascar.
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’.