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The genera of Leguminosae-Caesalpinioideae & Swartzieae

L. Watson and M.J. Dallwitz

Stenodrepanum Harms

Type species: S. bergii Harms.

Habit and leaf form. Erect shrubs, or herbs; without specialized ‘short shoots’; unarmed.

Phyllotaxy spiral. The leaves compound; bipinnate (ending in a single pinna); with opposite or sub-opposite pinnae; with rachides adaxially ridged. The leaflets very small, many per leaf. Stipules present, persistent and conspicuous in mature leaves; membranous; not connate. Stipels absent.

Inflorescence and floral morphology. The inflorescences unbranched; simple racemes. The flowers not distichous. Bracteoles absent at anthesis.

The flowers hermaphrodite; pentamerous. Floral tube length relative to total hypanthium + calyx length 0.25. Hypanthium present; cupular. The perianth comprising distinct calyx and corolla. Calyx 5; covering the rest of the flower in bud; polysepalous; markedly irregular (with the lowermost sepal oblong-obovate to oblong and slightly broader than the others, which are more lanceolate). Corolla present; slightly irregular to very irregular (the petals subequal, four of them oblong-lanceolate above their claws, the other broader and obovate); slightly exceeding the sepals, 5; without greatly reduced members; polypetalous. Petals clawed (the claws glandular-verruculose). The androecium comprising 10 members (the filaments glandular); comprising only fertile stamens. Fertile stamens 10. Anthers dehiscing introrsely. Ovary glandular-verruculose, shortly stipitate. Ovules numerous.

Fruit, seed and seedling. Fruit curved (narrowly linear-lanceolate and more or less falcate, slightly beaked, slightly constricted between the seeds); not noticeably winged. The mature valves with conspicuous, prominent, raised venation; conspicuous venation predominantly longitudinal (obliquely so). Seeds endospermic; with a straight or slightly oblique radicle.

Transverse section of lamina. Druses absent from the mesophyll. Mesophyll secretory cavities absent. Adaxial hypodermis absent. Leaf girders absent. 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 not seen. No compound or branched eglandular hairs seen. Capitate glands not seen. Expanded and embedded hair-feet absent. Adaxial: Adaxial interveinal epidermal cell walls straight in optical section; not conspicuously pitted; thin. Stomata adaxially common and widespread. Abaxial: Abaxial stomata not predominantly paracytic. Abaxial epidermis not papillate. Abaxial interveinal epidermal cell walls straight, or gently undulating; not conspicuously pitted in optical section; scarcely staining with safranin; thin.

Species number and distribution. 1 species (S. bergii). Argentina.

Tribe. Caesalpinieae.


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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’.

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