The genera of Leguminosae-Caesalpinioideae & Swartzieae
Type species: E. spectabilis van Steenis & de Wit.
Habit and leaf form. Trees; unarmed.
Phyllotaxy spiral. The leaves compound; pinnate; paripinnate. The leaflets relatively few per leaf (usually 3 pairs); opposite or sub-opposite; petiolulate; without noticeably twisted petiolules; symmetrical or nearly so; pinnately veined, with a predominant midrib; 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 axillary; branched; of racemose units; fascicles and panicles (in fasciculate panicles). The flowers not distichous. Bracts persistent beyond anthesis. Bracteoles present; small, not enclosing the flower buds; absent at anthesis; not valvate; free.
The flowers small; hermaphrodite; not pentamerous throughout; departing from pentamery in the calyx, in the corolla, and in the androecium; white or green. Floral tube length relative to total hypanthium + calyx length about 0.5. Hypanthium present. Calyx 4; covering the rest of the flower in bud; polysepalous; members imbricate. Corolla present; very irregular; 1–3; including greatly reduced members, or without greatly reduced members; polypetalous. Petals clawed; white. The androecium comprising 2 members; with united members; members all more or less equal in length; comprising only fertile stamens. Fertile stamens borne abaxially on a ringlike extension of the hypanthium, only 2. Anthers attached well above the base of the connective; dehiscing longitudinally. Ovary stipitate; free, or eccentric, with the stipe adnate. Ovules few.
Fruit, seed and seedling. Fruit a two-valved pod; valves twisting and enrolling during dehiscence. The mature valves without prominent venation. Seeds with a straight or slightly oblique radicle; amyloid-positive. Cotyledons 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 dorsiventral. Mesophyll without unaligned fibres or sclereids. Minor veins mainly with abundant accompanying fibres.
Leaf lamina epidermes. Epidermal crystals present; prisms. Simple unbranched hairs common. 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; conspicuously pitted; thick. Stomata adaxially common and widespread, or adaxially very rare. Abaxial: Abaxial stomata predominantly paracytic. Abaxial epidermis not papillate. Abaxial interveinal epidermal cell walls straight, or gently undulating; conspicuously pitted in optical section; staining normally with safranin; thick.
Pollen ultrastructure. Tectum striate. Length of colpi less than one half pole to pole distance.
Species number and distribution. 1 species (E. spectabilis). Borneo.
Tribe. Detarieae; Amherstieae clade of Bruneau et al. (2008).
Miscellaneous. Illustrations: • E. spectabilis: Fl. Males. 12 (1996).
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’.