The Genera of Leguminosae-Caesalpinioideae and Swartzieae
| The Genera of Leguminosae-Caesalpinioideae and Swartzieae | |
Habit and leaf form. Trees, or shrubs (with thick branchlets); without tendrils; unarmed. Leaves and inflorescences crowded on ‘short shoots’. Phyllotaxy spiral. Leaves compound (silky when young); bipinnate; with opposite or sub-opposite pinnae (few pairs); with alternate leaflets. Leaflets petiolulate; with petiolules not noticeably twisted. Stipules absent or early caducous or very inconspicuous; neither leafy nor spinescent; not connate. Stipels absent.
Inflorescence and floral morphology. Flowers small; hermaphrodite; pentamerous; white or green; in simple racemes (spicate), or in panicles (of interrupted spikes); not distichous. Inflorescences of racemose units. Bracts absent at anthesis (caducous, small). Bracteoles absent; absent at anthesis. Length of floral tube relative to total hypanthium plus calyx length, about 0.75. Calyx gamosepalous; not covering the rest of the flower in bud; more or less regular; 5 partite; imbricate. Corolla present; slightly zygomorphic; polypetalous; without any greatly reduced petals. Petals white; 5; imbricate; imbricate-ascending. Androecium of ten parts; members all free of one another (the filaments very short, connective with an inflexed glandular appendage); members all more or less equal in length, or members markedly unequal; without staminodia. Fertile stamens 10. Anthers attached at base of connective (but anther sagittate below). Ovary sessile or subsessile, or stipitate; free. Stigma funnel-shaped, split down one side; style very short. Ovules few, or solitary.
Fruit, seed and seedling. Fruit indehiscent; not becoming woody; with prominent, raised veins; with veins other than the longitudinal ones predominating; not winged; without markedly twisting or enrolling valves. Seeds endospermic; with a straight or slightly oblique radicle; amyloid-negative. Cotyledons flat; of Type 2; hypogeal.
Transverse section of lamina. Leaves without conspicuous phloem transfer cells in the minor veins. Druses 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. 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; not conspicuously pitted; medium-thin. 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; staining normally with safranin; thin.
Wood anatomy. Wood without septate fibres; not storied; without normal intercellular canals; without traumatic canals. Intervascular pits medium to large.
Pollen ultrastructure. Tectum reticulate; rugulose reticulate. Length of colpi greater than one half pole to pole distance (without a margocolpus).
Cytology, geography, etc. Basic chromosome number, x = 14. 2n = 28. 1 species. Africa. West and southern Africa. Not 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’.