The genera of Leguminosae-Caesalpinioideae & Swartzieae
Schizosiphon K. Schum., Pseudocynometra Kuntze
Type species: M. grandiflora Scheff.
Habit and leaf form. Trees, or shrubs (rarely); unarmed.
Phyllotaxy distichous. The leaves compound (when young, enclosedin buds several cm long, with imbricate, cartilaginous bud scales); pinnate, or bifoliolate (rarely); paripinnate. The leaflets many per leaf, or few per leaf; opposite or sub-opposite (in (1-)2–5 pairs); petiolulate, or sessile to sub-sessile; without noticeably twisted petiolules; glaucous below, markedly asymmetrical; acuminate, pinnately veined, with a predominant midrib (with this conspicuously displaced towards the upper margin); without a continuous marginal nerve. Stipules absent or early caducous or very inconspicuous in mature leaves (very caducous); membranous (linear, apically dilated); not connate. Stipels absent.
Inflorescence and floral morphology. The inflorescences on the leafless branches, axillary; unbranched; sessile, globular and densely contraced simple racemes. The flowers not distichous. Bracts paired at the pedicel bases, the lower much broader than the upper absent at anthesis to persistent beyond anthesis. Bracteoles present; somewhat showy, but small, not enclosing the flower buds; persistent beyond anthesis to absent at anthesis; not valvate; free.
The flowers hermaphrodite; not pentamerous throughout; departing from pentamery in the calyx and in the androecium; white or green. Floral tube length relative to total hypanthium + calyx length about 0.25–0.4. Hypanthium present; tubular, or campanulate. The perianth comprising distinct calyx and corolla. Calyx 4; covering the rest of the flower in bud; polysepalous; more or less regular (the sepals subequal); members imbricate. Corolla present (about equaling the calyx); slightly irregular; 5 (the petals narrowly linear); without greatly reduced members; polypetalous. Petals sessile; imbricate; white. Disk absent. The androecium comprising 15–80 members; not declinate; with united members (often having the long, slender filaments basally joined), or members all free of one another; members all more or less equal in length; comprising only fertile stamens. Fertile stamens 15–80. Anthers attached well above the base of the connective (and the connective at least sometimes prolonged apically); dehiscing longitudinally. Ovary stipitate; free. Stigma somewhat dilated to not dilated (on the slender, exserted style). Ovules few.
Fruit, seed and seedling. Fruit indehiscent; arcuate-ovoid, thick and turgid; without markedly twisting or enrolling valves; becoming woody. The mature valves rugose without prominent venation. Seeds non-endospermic; with a straight or slightly oblique radicle; amyloid-positive.
Transverse section of lamina. Leaves with conspicuous phloem transfer cells in the minor veins, or without conspicuous phloem transfer cells in the minor veins. Druses absent from the mesophyll. Mesophyll secretory cavities absent. Adaxial hypodermis absent. Leaf girders absent. Laminae dorsiventral. Mesophyll exhibiting fibres or sclereids which are unaligned with the vascular bundles. Minor veins mainly with abundant accompanying fibres.
Leaf lamina epidermes. Epidermal crystals not seen either adaxially or abaxially. Simple unbranched hairs common; smooth. No compound or branched eglandular hairs seen. Capitate glands not seen. Hooked hairs not seen. Cassieae-type leaf pseudo-glands not seen. Expanded and embedded hair-feet absent. Basally bent hairs absent. Adaxial: Adaxial interveinal epidermal cell walls markedly sinuous in high-focus optical section; conspicuously pitted, or not conspicuously pitted; of medium thickness. 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; not conspicuously pitted in optical section; staining normally with safranin; of medium thickness.
Pollen ultrastructure. Tectum punctate, or reticulate; rugulose punctate; rugulose reticulate. Length of colpi greater than one half pole to pole distance.
Species number and distribution. 20–25 species (excluding numerous species now referred to Gilbertiodendron). Malaysia, New Guinea, Fiji, India to S.E. Asia, Australia.
Tribe. Detarieae; Amherstieae clade of Bruneau et al. (2008).
Comments. Widely cultivated.
Miscellaneous. Illustrations: • M. brassii and M. rosea: Ding Hou, Fl. Malesiana 12 (1995). • M. psilogyna, e.m. scanned pollen (Graham & Barker, 1981). • M. lenticellata, 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’.