The Genera of Leguminosae-Caesalpinioideae and Swartzieae
| The Genera of Leguminosae-Caesalpinioideae and Swartzieae | |
Habit and leaf form. Trees, or shrubs (rare); without tendrils; armed (with thorns). Leaves and inflorescences crowded on ‘short shoots’. Phyllotaxy spiral (with supernumerary axillary buds). Leaves compound (the leaflets often serrate); pinnate, or bipinnate (often both, on same specimen); with alternate pinnae; with alternate leaflets; paripinnate. Leaflets small-medium; with petiolules not noticeably twisted. Stipules absent or early caducous or very inconspicuous; neither leafy nor spinescent. Stipels absent.
Inflorescence and floral morphology. Flowers small; unisexual; pentamerous, or not pentamerous throughout; departing from pentamery in the calyx, or in the corolla, or in the androecium (in combinations); white or green; in simple racemes, or in fascicled inflorescences, or in panicles; not distichous. Inflorescences of racemose units, or of cymose units, or of solitary flowers. Bracts absent at anthesis (small caducous scales). Bracteoles absent; absent at anthesis. Hypanthium present. Length of floral tube relative to total hypanthium plus calyx length, about 0.25–0.5. Calyx polysepalous; not covering the rest of the flower in bud; more or less regular; 3–5 partite. Corolla present; actinomorphic; polypetalous; without any greatly reduced petals. Petals white; 3–5; imbricate; imbricate-ascending. Clawed petals absent. Androecium of fewer than ten parts, or of ten parts; members all free of one another; members all more or less equal in length; without staminodia. Fertile stamens 6–10. Anthers attached well above base of connective. Dehiscence lateral; longitudinal. Ovary sessile or subsessile; free. Stigma not peltate (generally bilobed, the style short). Ovules few, or numerous.
Fruit, seed and seedling. Fruit a two-valved pod, or indehiscent; not becoming woody; straight, or curved; not winged. Seeds endospermic; with a straight or slightly oblique radicle; amyloid-negative; with galactomannan. Cotyledons flat; 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 lacking accompanying fibrous tissue.
Leaf lamina epidermes. Epidermal crystals not seen either adaxially or abaxially. Simple unbranched hairs common; scabrid. 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; not conspicuously pitted; of medium thickness. Stomata adaxially very rare. Abaxial stomata not predominantly paracytic (mixed cyclocytic, actinocytic, anomcytic). Abaxial epidermis not papillate. Abaxial interveinal epidermal cell walls straight, or gently undulating; not conspicuously pitted in optical section; scarcely staining with safranin, or staining normally with safranin; of medium thickness.
Wood anatomy. Wood without septate fibres; not storied. Intervascular pits very small.
Pollen ultrastructure. Tectum reticulate; finely to moderately regularly reticulate. Length of colpi greater than one half pole to pole distance (no margocolpus). Foot layer of pollen wall with obvious projections.
Cytology, geography, etc. Basic chromosome number, x = 14. 2n = 28. 14 species. Tropical and subtropical. 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’.