The Genera of Leguminosae-Caesalpinioideae and Swartzieae
| The Genera of Leguminosae-Caesalpinioideae and Swartzieae | |
Habit and leaf form. Trees, or shrubs; without tendrils; unarmed. Phyllotaxy spiral. Leaves compound; bipinnate; with opposite or sub-opposite leaflets, or with alternate leaflets; with adaxially grooved rachides. Leaflets with petiolules not noticeably twisted. Stipules absent or early caducous or very inconspicuous; neither leafy nor spinescent. Stipels absent.
Inflorescence and floral morphology. Flowers hermaphrodite; pentamerous; in panicles (of racemes); not distichous. Inflorescences of racemose units. Bracts absent at anthesis. Bracteoles absent; absent at anthesis. Hypanthium present. Length of floral tube relative to total hypanthium plus calyx length, about 0.25. Calyx polysepalous; covering the rest of the flower in bud; more or less regular, or markedly zygomorphic; 5 partite (the sepals with hyaline margins); imbricate. Corolla present; slightly zygomorphic, or very zygomorphic; polypetalous; without any greatly reduced petals. Petals yellow; 5 (the petals spathulate and corrugated); imbricate. Clawed petals present. Androecium of ten parts; members all free of one another; without staminodia. Fertile stamens 10. Dehiscence introrse. Ovary sessile or subsessile; free. Stigma peltate (the style pilose). Ovules few.
Fruit, seed and seedling. Fruit a two-valved pod; becoming distinctly woody; not winged; without markedly twisting or enrolling valves (revolute). Seeds non-endospermic; with a straight or slightly oblique radicle; amyloid-negative; with starch.
Transverse section of lamina. Leaves without conspicuous phloem transfer cells in the minor veins. Druses common in the mesophyll. Mesophyll secretory cavities (gland-dots) common; epithelium-lined, or without a lining of epithelium. Adaxial hypodermis absent. Leaf girders absent. 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, or not seen; 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, or absent. Adaxial interveinal epidermal cell walls straight in optical section, or markedly sinuous in high-focus optical section; conspicuously pitted. Stomata adaxially very rare. Abaxial stomata predominantly paracytic. Abaxial epidermis not papillate. Abaxial interveinal epidermal cell walls straight, or gently undulating, or markedly sinuous in high-focus optical section; conspicuously pitted in optical section; staining normally with safranin; of medium thickness to medium-thin.
Wood anatomy. Wood with septate fibres; not storied.
Pollen ultrastructure. Tectum reticulate; finely to moderately regularly reticulate. Length of colpi greater than one half pole to pole distance (without a margocolpus). Foot layer of pollen wall with obvious projections.
Cytology, geography, etc. Basic chromosome number, x = 11. 2n = 22. 6 species. Madagascar and tropical 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’.