The Genera of Leguminosae-Caesalpinioideae and Swartzieae
| The Genera of Leguminosae-Caesalpinioideae and Swartzieae | |
Habit and leaf form. Trees; without tendrils; unarmed. Leaves compound; bipinnate; with opposite or sub-opposite pinnae; with opposite or sub-opposite leaflets. Leaflets many per leaf; petiolulate. Stipules absent or early caducous or very inconspicuous; neither leafy nor spinescent; not connate. Stipels absent.
Inflorescence and floral morphology. Flowers large; hermaphrodite; pentamerous; coloured (greenish yellow); in simple racemes and in panicles; not distichous. Inflorescences axillary (racemes), or terminal (panicles of 2–3 racemes); of racemose units. Bracts absent at anthesis (caducous, small). Bracteoles present; small, not enclosing the flower buds; absent at anthesis. Hypanthium present (the exposed part red). Length of floral tube relative to total hypanthium plus calyx length, about 0.5. Calyx polysepalous; covering the rest of the flower in bud, or not covering the rest of the flower in bud; 5 partite; imbricate (slightly). Corolla present; actinomorphic to slightly zygomorphic; without any greatly reduced petals. Petals 5. Disk present and conspicuous. Androecium of fewer than ten parts; members all free of one another; without staminodia. Fertile stamens 5 (alternisepalous). Anthers attached well above base of connective. Dehiscence introrse. Ovary stipitate; free. Stigma not peltate (the style short). Ovules numerous.
Fruit, seed and seedling. Fruit a two-valved pod; not becoming woody; straight; conspicuously winged (on the adaxial suture); without markedly twisting or enrolling valves. Seeds endospermic (sometimes winged); arillate (small); with a straight or slightly oblique radicle; amyloid-negative. Cotyledons of Type 2; epigeal.
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 absent. 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 interveinal epidermal cell walls straight in optical section; conspicuously pitted; thick. Stomata adaxially very rare. 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; medium-thin.
Pollen ultrastructure. Tectum punctate; rugulose punctate. Length of colpi greater than one half pole to pole distance (no margocolpus).
Cytology, geography, etc. Basic chromosome number, x = 12. 2n = 24. 2 species. Indomalayan region. Widely cultivated.
Tribe. Caesalpinieae.
The interactive key provides access to the character list, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting specified attributes, and summaries of attributes within groups of taxa.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 1993 onwards. The genera of Leguminosae-Caesalpinioideae and Swartzieae: descriptions, identification, and information retrieval. In English and French; French translation by E. Chenin. Version: 19th October 2005. http://delta-intkey.com’.