The Genera of Leguminosae-Caesalpinioideae and Swartzieae
| The Genera of Leguminosae-Caesalpinioideae and Swartzieae | |
Habit and leaf form. Shrubs; without tendrils; unarmed. Without specialized ‘short shoots’. Phyllotaxy spiral. Leaves compound; pinnate; paripinnate; with rachides adaxially ridged. Venation neither palmate nor parallel nor fan-like. Leaflets few per leaf (with purple gland dots below); alternate; with petiolules not noticeably twisted. Stipels absent.
Inflorescence and floral morphology. Flowers hermaphrodite; pentamerous; in simple corymbs (few flowered); not distichous. Inflorescences terminal; of racemose units. Bracteoles absent; absent at anthesis. Hypanthium present. Length of floral tube relative to total hypanthium plus calyx length, about 0.25. Calyx polysepalous; covering the rest of the flower in bud; more or less regular; 5 partite; not imbricate. Corolla present; slightly zygomorphic; polypetalous; without any greatly reduced petals. Petals 5 (spathulate); imbricate-ascending. Clawed petals present. Androecium of ten parts; members all free of one another; without staminodia. Fertile stamens 10. Anthers attached well above base of connective. Dehiscence introrse. Ovary stipitate. Ovules few.
Fruit, seed and seedling. Fruit a two-valved pod; not becoming woody; short beaked, scarcely falcate; not winged. Seeds non-endospermic; with a straight or slightly oblique radicle. Cotyledons not flat.
Transverse section of lamina. Leaves without conspicuous phloem transfer cells in the minor veins. Druses absent from the mesophyll. Mesophyll secretory cavities absent. Adaxial hypodermis absent. Leaf girders absent. Laminae isobilateral, with adaxial and abaxial palisades. 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; smooth. No compound or branched eglandular hairs seen. Capitate glands present. Hooked hairs not seen. Cassieae-type leaf pseudo-glands not seen. Expanded and embedded hair-feet absent. Basally bent hairs present. Adaxial interveinal epidermal cell walls straight in optical section, or markedly sinuous in high-focus optical section; not conspicuously pitted; of medium thickness. Stomata adaxially common and widespread. Abaxial stomata not predominantly paracytic (cyclocytic). Abaxial epidermis not papillate. Abaxial interveinal epidermal cell walls straight, or gently undulating, or markedly sinuous in high-focus optical section; not conspicuously pitted in optical section; staining normally with safranin; of medium thickness.
Pollen ultrastructure. Tectum reticulate; finely to moderately regularly reticulate. Length of colpi greater than one half pole to pole distance (with a margocolpus). Foot layer of pollen wall with obvious projections.
Cytology, geography, etc. Basic chromosome number, x = 12. 2n = 28. 2 species. Tropical Africa. Not widely cultivated.
Tribe. Caesalpinieae.
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’.