The Genera of Leguminosae-Caesalpinioideae and Swartzieae
The Genera of Leguminosae-Caesalpinioideae and Swartzieae |
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Habit and leaf form. Trees, or shrubs; without tendrils; unarmed. Phyllotaxy spiral. Leaves simple, or two-lobed. Venation palmate, parallel or fan-like. Stipules absent or early caducous or very inconspicuous; neither leafy nor spinescent.
Inflorescence and floral morphology. Flowers hermaphrodite; pentamerous; coloured; in simple racemes (short, fascicle-like); not distichous. Inflorescences on older branches. Bracteoles present; small, not enclosing the flower buds; absent at anthesis, or persistent beyond anthesis (rare). Length of floral tube relative to total hypanthium plus calyx length, about 0.25. Calyx gamosepalous; not covering the rest of the flower in bud; markedly zygomorphic; 5 partite (shortly, broadly 5-toothed); not imbricate. Corolla present; very zygomorphic; polypetalous. Petals red; 5; imbricate; imbricate-ascending. Clawed petals present. Disk present and conspicuous. Androecium of ten parts; members all free of one another; members markedly unequal; without staminodia. Fertile stamens 10. Anthers attached at base of connective, or attached well above base of connective. Dehiscence longitudinal. Ovary stipitate; free. Stigma not peltate (the style filiform). Ovules numerous.
Fruit, seed and seedling. Fruit a two-valved pod (flat, thin); not becoming woody; straight; conspicuously winged; without markedly twisting or enrolling valves. Seeds endospermic; not arillate (the hilum circular); with a straight or slightly oblique radicle; amyloid-negative. Cotyledons flat; of Type 2; epigeal.
Transverse section of lamina. 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 not seen. 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; thick. Stomata adaxially very rare. Abaxial stomata not predominantly paracytic (anomocytic). 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 with septate fibres; storied.
Cytology, geography, etc. Basic chromosome number, x = 7. 2n = 14. 6 species. Western Eurasia, U.S.S.R., Mediterranean, and North America. North temperate. 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: 22nd March 2009. http://delta-intkey.com’.