The genera of Leguminosae-Caesalpinioideae & Swartzieae
Cf. Cyanothyrsus harms, Paradaniellia Rolfe. A taxon of uncertain taxonomic status, represented by about 10 specific names.
Type species: D. thurifera J.J. Benn.
Habit and leaf form. Resinous trees, or shrubs; unarmed.
Phyllotaxy spiral. The leaves compound; pinnate; paripinnate. The leaflets many per leaf; opposite or sub-opposite (mostly), or alternate (rarely); petiolulate; without noticeably twisted petiolules; symmetrical or nearly so; without a continuous marginal nerve. Stipules absent or early caducous or very inconspicuous in mature leaves; membranous; intrapetiolar, not connate (enfolding bud). Stipels absent.
Inflorescence and floral morphology. The inflorescences terminal; branched; of racemose units; panicles (of racemes). The flowers not distichous. Bracts absent at anthesis. Bracteoles present; relatively large and enclosing the flower buds; absent at anthesis, or persistent beyond anthesis; not valvate.
The flowers hermaphrodite; not pentamerous throughout; departing from pentamery in the calyx; coloured. Floral tube length relative to total hypanthium + calyx length about 0.25. Hypanthium present; shortly, asymmetrically cupular. Calyx deciduous, 4; covering the rest of the flower in bud, or not covering the rest of the flower in bud; not Swartzieae type; polysepalous; more or less regular; members imbricate. Corolla present; very irregular; 5; including greatly reduced members; polypetalous. Petals sessile; imbricate; imbricate-ascending. Disk absent. The androecium comprising 10 members; with united members, or members all free of one another; members all more or less equal in length; comprising only fertile stamens. Fertile stamens 10. Anthers attached well above the base of the connective; dehiscing longitudinally. Ovary stipitate; eccentric, with the stipe adnate. Stigma inconspicuously dilated, or not dilated. Ovules numerous.
Fruit, seed and seedling. Fruit a two-valved pod; curved; valves twisting and enrolling during dehiscence; not becoming woody. The mature valves without prominent venation. Seeds non-endospermic; arillate (with cupular aril and long funicle); with a straight or slightly oblique radicle; amyloid-positive. Cotyledons flat; 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 common in the mesophyll, or absent from the mesophyll. Mesophyll secretory cavities (gland-dots) common; epithelium-lined. 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, or druses. Simple unbranched hairs common, or not seen. 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: Adaxial interveinal epidermal cell walls straight in optical section; conspicuously pitted, or not conspicuously pitted; thick. Stomata adaxially very rare. Abaxial: Abaxial stomata predominantly paracytic. Abaxial epidermis not papillate. Abaxial interveinal epidermal cell walls straight, or gently undulating; conspicuously pitted in optical section; staining normally with safranin; thick.
Wood anatomy. Wood without septate fibres; storied; with normal intercellular canals; without traumatic canals. Intervascular pits medium to large.
Pollen ultrastructure. Tectum punctate; rugulose punctate. Length of colpi greater than one half pole to pole distance.
Cytology. Basic chromosome number, x = 11. 2n = 22.
Species number and distribution. About 10 species. Tropical West Africa.
Miscellaneous. Illustrations: • D. oliveri: Brenan, Fl. Tropical East Africa (1967). • D. klainei, D. ogea and D. pynaertii: Aubréville, Flore du Gabon (1968). • D. soyauxii (as Cyanothyrsus), with Oxystigma buchholzii and Oxystigma buchholzii): Bot. Jahrb. 26.
We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or the interactive key, which allows access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, distributions of character states within any set of taxa, geographical distribution, and classification. See also Guidelines for using data taken from Web publications.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 1993 onwards. The genera of Leguminosae-Caesalpinioideae and Swartzieae: descriptions, illustrations, identification, and information retrieval. In English and French. Version: 22nd March 2017. delta-intkey.com/caes’.