The Genera of Leguminosae-Caesalpinioideae and Swartzieae
| The Genera of Leguminosae-Caesalpinioideae and Swartzieae | |
Habit and leaf form. Trees, or shrubs; without tendrils. Phyllotaxy distichous, or spiral. Leaves two-lobed. Venation palmate, parallel or fan-like. Stipules absent or early caducous or very inconspicuous, or present, persistent and conspicuous; neither leafy nor spinescent; not connate. Stipels absent.
Inflorescence and floral morphology. Flowers hermaphrodite, or unisexual; pentamerous (rare), or not pentamerous throughout; coloured; in simple racemes, or in simple corymbs, or in panicles; not distichous. Inflorescences axillary (rare), or terminal; of racemose units. Bracts absent at anthesis. Bracteoles present; small, not enclosing the flower buds; absent at anthesis, or persistent beyond anthesis. Hypanthium present. Length of floral tube relative to total hypanthium plus calyx length, about 0.2–1 (estimated). Calyx gamosepalous; covering the rest of the flower in bud; markedly zygomorphic (spathaceous, splitting down one side but otherwise remaining entire for almost its whole length); not imbricate. Corolla present; slightly zygomorphic; polypetalous; without any greatly reduced petals. Petals white, or yellow, or red; 5 (rarely 2–4); imbricate; imbricate-ascending. Clawed petals present, or absent. Disk present and conspicuous, or absent. Androecium of fewer than ten parts, or of ten parts; with united members, or members all free of one another; members markedly unequal (2 whorls usually of different lengths); with staminodia, or without staminodia. Fertile stamens 1–10. Anthers attached well above base of connective. Dehiscence longitudinal. Ovary stipitate; free, or excentric with adnate stipe. Ovules few, or numerous.
Fruit, seed and seedling. Fruit a two-valved pod; becoming distinctly woody, or not becoming woody (leathery to woody); straight (oblong to linear); not winged; without markedly twisting or enrolling valves. Seeds endospermic, or non-endospermic; arillate (the hilum crescentic); with a straight or slightly oblique radicle; amyloid-negative. Cotyledons flat; epigeal, or hypogeal.
Transverse section of lamina. Leaves without conspicuous phloem transfer cells in the minor veins. Druses common in the mesophyll, or absent from 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; scabrid, or 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 present. Adaxial interveinal epidermal cell walls straight in optical section, or markedly sinuous in high-focus optical section; conspicuously pitted, or not conspicuously pitted. Stomata adaxially common and widespread, or adaxially very rare. Abaxial stomata predominantly paracytic. Abaxial epidermis not papillate. Abaxial interveinal epidermal cell walls straight, or gently undulating; conspicuously pitted in optical section, or not conspicuously pitted in optical section; scarcely staining with safranin, or staining normally with safranin.
Wood anatomy. Wood with septate fibres; storied, or not storied; without normal intercellular canals; without traumatic canals. Intervascular pits very small.
Pollen ultrastructure. Tectum reticulate, or striate; finely to moderately regularly reticulate, or rugulose reticulate, or verrucose reticulate; reticulate striate. Length of colpi greater than one half pole to pole distance, or less than one half pole to pole distance.
Cytology, geography, etc. Basic chromosome number, x = 13, or 14. 2n = 24, or 26, or 28, or 42, or 56. About 100 species. In warm regions. Widely cultivated.
Tribe. Cercideae.
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’.