The Genera of Leguminosae-Caesalpinioideae and Swartzieae
| The Genera of Leguminosae-Caesalpinioideae and Swartzieae | |
= Parkinsonia.
Habit and leaf form. Trees, or shrubs (the branches often twisted); without tendrils; armed (with short straight spines at nodes). Leaves and inflorescences crowded on ‘short shoots’. Phyllotaxy spiral. Leaves compound (small); bipinnate (1–2 pairs of pinnae); with opposite or sub-opposite pinnae; with opposite or sub-opposite leaflets; with rachides adaxially ridged. Leaflets many per leaf; petiolulate; with petiolules not noticeably twisted. Stipules absent or early caducous or very inconspicuous; neither leafy nor spinescent. Stipels absent.
Inflorescence and floral morphology. Flowers hermaphrodite; pentamerous; coloured; in simple racemes (short, lax); not distichous. Inflorescences of racemose units. Bracts small. Bracteoles absent; absent at anthesis. Length of floral tube relative to total hypanthium plus calyx length, about 0.25. Calyx covering the rest of the flower in bud; more or less regular; 5 partite; not imbricate. Corolla present; very zygomorphic; polypetalous; without any greatly reduced petals. Petals yellow; 5; imbricate; imbricate-ascending. Clawed petals present. Disk present and conspicuous. 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; free. Stigma not peltate. Ovules numerous.
Fruit, seed and seedling. Fruit indehiscent; not becoming woody; straight; not internally septate; with prominent, raised veins; with veins other than the longitudinal ones predominating; not winged; without markedly twisting or enrolling valves. Seeds endospermic; with a straight or slightly oblique radicle; amyloid-negative; with galactomannan. Cotyledons not flat; of Type 2; epigeal.
Transverse section of lamina. Leaves without conspicuous phloem transfer cells in the minor veins. Druses common in the mesophyll. Mesophyll secretory cavities absent. Adaxial hypodermis absent. Leaf girders absent. Laminae isobilateral, with adaxial and abaxial palisades, or 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; smooth. 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. Basally bent hairs absent. Adaxial interveinal epidermal cell walls straight in optical section; conspicuously pitted; medium-thin. Stomata adaxially common and widespread. Abaxial stomata not predominantly paracytic (anomcytic, actinocytic and cyclocytic). Abaxial epidermis not papillate. Abaxial interveinal epidermal cell walls straight, or gently undulating, or markedly sinuous in high-focus optical section; conspicuously pitted in optical section; scarcely staining with safranin, or staining normally with safranin; medium-thin.
Wood anatomy. Wood without septate fibres; not storied. Intervascular pits very small.
Pollen ultrastructure. Tectum reticulate; finely to moderately regularly reticulate. Length of colpi greater than one half pole to pole distance (without a margocolpus). Foot layer of pollen wall with obvious projections.
Cytology, geography, etc. 10 species. Warm America. 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’.