The Genera of Leguminosae-Caesalpinioideae and Swartzieae
| The Genera of Leguminosae-Caesalpinioideae and Swartzieae | |
Habit and leaf form. Trees; without tendrils; unarmed. Phyllotaxy spiral. Leaves compound; pinnate; imparipinnate, or paripinnate. Leaflets few per leaf; symmetrical or nearly so at their bases; alternate; with a strong, continuous marginal nerve; petiolulate; with petiolules not noticeably twisted. Stipules present, persistent and conspicuous. Stipels absent.
Inflorescence and floral morphology. Flowers large; hermaphrodite; not pentamerous throughout; departing from pentamery in the calyx; white or green; in simple racemes (short, crowded); distichous (pedicels very short). Inflorescences subterminal racemes. Bracts absent at anthesis. Bracteoles present; small, not enclosing the flower buds; absent at anthesis; not valvate; free. Hypanthium absent (infilled). Calyx polysepalous; 4 partite; imbricate (but subvalvate); not Swartzieae type. Corolla present; slightly zygomorphic; polypetalous; without any greatly reduced petals. Petals 5 (obovate-spathulate); imbricate; imbricate-ascending. Clawed petals present. Androecium of ten parts; with united members (9 connate basally, the upper one free); without staminodia. Fertile stamens 10 (alternate filaments basally villous). Anthers attached well above base of connective. Dehiscence longitudinal. Ovary stipitate; free, or excentric with adnate stipe (interpretive problem). Ovules few, or numerous, or solitary.
Fruit, seed and seedling. Fruit a two-valved pod; becoming distinctly woody; not winged; valves twisting and enrolling during dehiscence. Seeds arillate; with a straight or slightly oblique radicle; amyloid-positive. Cotyledons of Type 4; with a vascular system in one plane; epigeal.
Transverse section of lamina. Leaves with conspicuous phloem transfer cells in the minor veins. Druses absent from the mesophyll. Mesophyll secretory cavities (gland-dots) common; epithelium-lined. 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; 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 markedly sinuous in high-focus optical section; conspicuously pitted; thin. Stomata adaxially very rare. Abaxial stomata predominantly paracytic. Abaxial epidermis not papillate. Abaxial interveinal epidermal cell walls markedly sinuous in high-focus optical section; conspicuously pitted in optical section; scarcely staining with safranin; of medium thickness.
Wood anatomy. Wood without septate fibres; storied, or not storied; without normal intercellular canals; without traumatic canals. Intervascular pits medium to large.
Pollen ultrastructure. Tectum reticulate; finely to moderately regularly reticulate. Length of colpi greater than one half pole to pole distance. Foot layer of pollen wall smooth.
Cytology, geography, etc. Basic chromosome number, x = 10. 2n = 20. 4 species. Tropical Africa. Widely cultivated.
Tribe. Detarieae.
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’.