The genera of Leguminosae-Caesalpinioideae & Swartzieae
~ Bauhinia sensu lato.
Including Tylosema (Schweinf.) Torre & Hillc., Schnella Wunderlin
Habit and leaf form. Climbers or scramblers (lianas or scandent shrubs); usually with tendrils; unarmed.
Phyllotaxy distichous. The leaves with Lysiphyllum and Lasiobema excluded, compound (section Palmatifolia only), or ostensibly simple, or two-lobed; when ostensibly simple or bilobed, palmately veined; sometimes bifoliolate (sometimes, in section Palmatifolia). The leaflets when bifoliolate, more or less markedly asymmetrical; palmately nerved. Stipules absent or early caducous or very inconspicuous in mature leaves; leafy, or membranous. Stipels absent.
Inflorescence and floral morphology. The inflorescences unbranched (always?); simple racemes and simple corymbs. The flowers not distichous. Bracts absent at anthesis, or persistent beyond anthesis. Bracteoles present; small, not enclosing the flower buds; absent at anthesis, or persistent beyond anthesis.
The flowers hermaphrodite; not pentamerous throughout; departing from pentamery in the calyx, or in the androecium, or in the calyx and in the androecium; coloured. Floral tube length relative to total hypanthium + calyx length about 0.5. Hypanthium present; more or less elongate, variously campanulate, infundibular or turbinate. Calyx 2–4, or 5; covering the rest of the flower in bud, or not covering the rest of the flower in bud; gamosepalous; more or less regular, or markedly irregular (then splitting irregularly into 2–5 lobes); members not imbricate. Corolla present; slightly irregular to very irregular; 5; without greatly reduced members; polypetalous. Petals clawed, or sessile; imbricate; imbricate-ascending; white, or yellow, or red. Disk absent (or represented by a red tubular outgrowth from the margin of the hypanthium). The androecium comprising (dubiously) 3–7 members; more or less declinate; members all free of one another; members markedly unequal; including staminodia. The staminodia large to minute. Fertile stamens 2 (usually), or 3 (rarely - section Palmatifolia). Anthers attached well above the base of the connective; dehiscing longitudinally (usually), or via pores or short slits (in Section Palmatifolia). Ovary stipitate; eccentric, with the stipe adnate. Stigma variously dilated, or not dilated. Ovules numerous.
Fruit, seed and seedling. Fruit a two-valved pod (but sometimes only tardily dehiscent); not drupaceous; straight; becoming woody, or not becoming woody. The mature valves without prominent venation. Seeds endospermic; arillate (with short, funicilar aril lobes and a crescentic hilum); with a straight or slightly oblique radicle.
Transverse section of lamina. Leaves without conspicuous phloem transfer cells in the minor veins. Druses common in 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 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 straight in optical section; not conspicuously pitted; thin. Stomata adaxially very rare. Abaxial: Abaxial stomata predominantly paracytic. Abaxial epidermis not papillate. Abaxial interveinal epidermal cell walls straight, or gently undulating; not conspicuously pitted in optical section; scarcely staining with safranin; thin.
Wood anatomy. Wood without septate fibres.
Pollen ultrastructure. Tectum punctate. Length of colpi greater than one half pole to pole distance.
Cytology. 2n = 24, or 26.
Species number and distribution. About 50 species. Tropical Asia to Australia.
Miscellaneous. Illustrations: • P. corymbosa: Bot Mag 108 (1882). • P. corymbosa: Bot. Reg. 1839, 47. • P. andersoni: Ding Hou, Fl. Malesiana 12 (1995). • P. ferruginea: Ding Hou, Fl. Malesiana 12 (1995). • P. fassoglensis (as Tylosema): Brenan, Fl. Tropical East Africa (1967). • P. (Tylosema) fassoglensis, 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’.