The Genera of Leguminosae-Caesalpinioideae and Swartzieae
| The Genera of Leguminosae-Caesalpinioideae and Swartzieae | |
Dicymbopsis Ducke
Habit and leaf form. Trees, or shrubs (rare); without tendrils; unarmed. Phyllotaxy spiral. Leaves compound; pinnate; paripinnate. Leaflets few per leaf; opposite or sub-opposite; petiolulate; with petiolules not noticeably twisted. Stipules absent or early caducous or very inconspicuous; neither leafy nor spinescent. Stipels absent.
Inflorescence and floral morphology. Flowers large (rather); hermaphrodite; not pentamerous throughout; departing from pentamery in the calyx; white or green; in panicles (racemose or corymbose); not distichous. Bracts absent at anthesis (caducous, thick and shell-like). Bracteoles present (thick, leathery); relatively large and enclosing the flower buds; persistent beyond anthesis; valvate. Hypanthium present (thick). Length of floral tube relative to total hypanthium plus calyx length, about 0.25. Calyx polysepalous; more or less regular, or markedly zygomorphic; 4 partite (the sepals often apically bifid); imbricate; not Swartzieae type. 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; members all more or less equal in length; without staminodia. Fertile stamens 10. Anthers attached well above base of connective. Dehiscence longitudinal. Ovary stipitate; free, or excentric with adnate stipe. Stigma peltate (the style involute in bud). Ovules numerous.
Fruit, seed and seedling. Fruit a two-valved pod; with prominent, raised veins; with veins other than the longitudinal ones predominating; conspicuously winged (adaxially), or not winged. Seeds with a straight or slightly oblique radicle; amyloid-positive.
Transverse section of lamina. Leaves with 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; prisms. Simple unbranched hairs common. 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. Adaxial interveinal epidermal cell walls markedly sinuous in high-focus optical section; conspicuously pitted; thick. 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; staining normally with safranin; thick.
Wood anatomy. Wood not storied.
Pollen ultrastructure. Tectum reticulate, or striate; rugulose reticulate; interwoven striate. Length of colpi greater than one half pole to pole distance, or less than one half pole to pole distance.
Cytology, geography, etc. 13 species. South and Central America. Tropical South America. Not widely cultivated.
Tribe. Detarieae (Amherstieae of Cowan and Polhill 1981).
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’.