The Genera of Leguminosae-Caesalpinioideae and Swartzieae
Habit and leaf form. Trees; without tendrils; unarmed. Phyllotaxy distichous, or spiral. Leaves compound; pinnate; imparipinnate. Leaflets few per leaf; alternate; with petiolules not noticeably twisted. Stipules absent or early caducous or very inconspicuous; neither leafy nor spinescent. Stipels absent.
Inflorescence and floral morphology. Flowers small (rather); unisexual; not pentamerous throughout; departing from pentamery in the calyx, in the corolla, and in the androecium; white or green; not distichous. Inflorescences axillary (small); of cymose units. 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; 3 partite; imbricate. Corolla present; actinomorphic; polypetalous; without any greatly reduced petals. Petals white; 3; imbricate; imbricate-ascending. Androecium of fewer than ten parts; without staminodia. Fertile stamens 3. Anthers attached at base of connective. Dehiscence longitudinal. Ovary stipitate; excentric with adnate stipe (abaxially). Ovules few.
Fruit, seed and seedling. Fruit indehiscent; not becoming woody; straight; conspicuously winged (narrowly, along upper suture). Seeds endospermic; with a straight or slightly oblique radicle; amyloid-negative; with galactomannan.
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 absent. Laminae dorsiventral. Mesophyll without unaligned fibres or sclereids. Minor veins mainly with abundant accompanying fibres.
Leaf lamina epidermes. Epidermal crystals present; druses. Simple unbranched hairs common; scabrid. No compound or branched eglandular hairs seen. Capitate glands not seen. Hooked hairs present. 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; conspicuously pitted; thick. Stomata adaxially very rare. Abaxial epidermis papillate interveinally; with papillae over-arching the stomata. Abaxial interveinal epidermal cell walls straight, or gently undulating; scarcely staining with safranin; thin.
Wood anatomy. Wood with septate fibres; storied. Intervascular pits medium to large.
Pollen ultrastructure. Tectum punctate; rugulose punctate. Length of colpi greater than one half pole to pole distance.
Cytology, geography, etc. Basic chromosome number, x = 14. 2n = 28. 1 species. Brazil, Peru. Argentina. Not widely cultivated.
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’.