The genera of Leguminosae-Caesalpinioideae & Swartzieae
Berlinia mengei de Wilde.
Type species: P. mengei (De Wild.) Hauman.
Habit and leaf form. Trees; unarmed.
Phyllotaxy distichous, or spiral. The leaves compound; pinnate; paripinnate. The leaflets few per leaf (2–3 pairs); opposite or sub-opposite; petiolulate; without noticeably twisted petiolules; membranous, gland-dotted, symmetrical or nearly so; without a continuous marginal nerve. Stipules absent or early caducous or very inconspicuous in mature leaves; membranous. Stipels absent.
Inflorescence and floral morphology. The inflorescences terminal; branched; of racemose units (?); panicles (the branches tending to be distichous). The flowers distichous, or not distichous. Bracts very small, caducous, absent at anthesis. Bracteoles present; relatively large and enclosing the flower buds; persistent beyond anthesis to absent at anthesis; valvate; free.
The flowers hermaphrodite; zygomorphic, pentamerous, or not pentamerous throughout; departing from pentamery when non-pentamerous, in the androecium. Hypanthium present. Calyx 5; covering the rest of the flower in bud; polysepalous; markedly irregular (with three free, sub-cordate sepals and the upper pair represented by lobes united almost to apex); members imbricate. Corolla present; very irregular; 5; including greatly reduced members (comprising two scales and three well developed members); polypetalous. Petals clawed (the three well developed ones), or sessile (the vestiges). The androecium comprising 10–13 members; members all free of one another; members exserted, all more or less equal in length; comprising only fertile stamens. Fertile stamens 10–13. Anthers attached well above the base of the connective; dehiscing longitudinally. Ovary stipitate; eccentric, with the stipe adnate. Stigma dilated (capitate). Ovules few.
Fruit, seed and seedling. Fruit a two-valved pod; flattened, oblong, straight; internally septate; valves twisting and enrolling during dehiscence; becoming woody. The mature valves with conspicuous, prominent, raised venation; conspicuous venation not predominantly longitudinal. Seeds with a straight or slightly oblique radicle.
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; without a lining of epithelium. Adaxial hypodermis absent. Leaf girders common (the veins transcurrent). Laminae dorsiventral. Mesophyll without unaligned fibres or sclereids. Minor veins lacking accompanying fibrous tissue.
Leaf lamina epidermes. Epidermal crystals not seen either adaxially or abaxially. 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 present; (at least some of them) thin-walled; hair feet (at least some of them) complex with vertical walls. Adaxial: Adaxial interveinal epidermal cell walls markedly sinuous in high-focus optical section; not conspicuously pitted; thin. Stomata adaxially common and widespread. Abaxial: Abaxial stomata predominantly paracytic. Abaxial epidermis not papillate. Abaxial interveinal epidermal cell walls markedly sinuous in high-focus optical section; not conspicuously pitted in optical section; staining normally with safranin; thin.
Pollen ultrastructure. Tectum striate; pole to pole striate. Length of colpi greater than one half pole to pole distance.
Species number and distribution. 1 species (P. mengei). Congo basin.
Tribe. Detarieae (Amherstieae of Cowan and Polhill 1981).
Miscellaneous. Illustrations: • P. mengei: Hauman, in Fl. du Congo Belge (1952).
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’.