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The genera of Leguminosae-Caesalpinioideae & Swartzieae

L. Watson and M.J. Dallwitz

Brachycylix (Harms) Cowan

Heterostemon vageleri

Type species: B. vageleri (Harms) Cowan.

Habit and leaf form. Shrubs; unarmed.

The leaves compound; pinnate; paripinnate. The leaflets few per leaf (bijugate); opposite or sub-opposite; petiolulate; with markedly twisted petiolules; without a continuous marginal nerve. Stipules absent or early caducous or very inconspicuous in mature leaves (caducous); membranous; not connate. Stipels absent.

Inflorescence and floral morphology. The inflorescences unbranched, or branched; when branched, of racemose units (then of ramuligerous, long-peduncled racemes); simple racemes, or panicles. The flowers not distichous. Bracts absent at anthesis (absent). Bracteoles present; small, not enclosing the flower buds; persistent beyond anthesis; not valvate; cupular, connate.

The flowers showy; hermaphrodite; not pentamerous throughout; departing from pentamery in the calyx; coloured. Floral tube length relative to total hypanthium + calyx length about 0.5. Hypanthium present. Calyx 4; not Swartzieae type; more or less regular; members imbricate. Corolla present; very irregular (comprising 3 large petals and 2 petalodia); 5; including greatly reduced members; polypetalous. Petals clawed and sessile; imbricate; yellow and red. The androecium comprising 9 members; with united members (forming an inequilateral tube); members markedly unequal; including staminodia. The staminodia 4; short. Fertile stamens 5. Anthers attached well above the base of the connective; dehiscing longitudinally. Ovary stipitate; eccentric, with the stipe adnate. Ovules numerous (7).

Transverse section of lamina. Druses absent from the mesophyll. Mesophyll secretory cavities absent. Adaxial hypodermis absent. Leaf girders common (the veins transcurrent), or 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; scabrid. 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; all medium to thick-walled; hair feet (at least some of them) complex with vertical walls. Basally bent hairs absent. Adaxial: Adaxial interveinal epidermal cell walls markedly sinuous in high-focus optical section; not conspicuously pitted; thin. Stomata adaxially very rare. Abaxial: 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; medium-thick.

Species number and distribution. 1 species (B. vageleri). Colombia.

Tribe. Detarieae.

Miscellaneous. Illustrations: • B. vageleri, flower (Cowan & Polhill, 1981).

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.’.