The genera of Leguminosae-Caesalpinioideae & Swartzieae
Type species: A. glabrifolium Dwyer.
Habit and leaf form. Trees; unarmed.
Phyllotaxy spiral. The leaves compound; pinnate; imparipinnate. The leaflets few per leaf; alternate; without noticeably twisted petiolules; symmetrical or nearly so; pinntely veined, with a predominant midrib. Stipules absent or early caducous or very inconspicuous in mature leaves. Stipels absent.
Inflorescence and floral morphology. The inflorescences terminal; branched; somewhat ambiguously of cymose units; complex, panicles. The flowers not distichous. Bracts absent at anthesis. Bracteoles present; small, not enclosing the flower buds; absent at anthesis.
The flowers small (tiny); hermaphrodite; not pentamerous throughout; departing from pentamery in the androecium, or in the calyx and in the androecium. Hypanthium absent, the androecium hypogynous. Calyx 4–5; covering the rest of the flower in bud; polysepalous; more or less regular, or markedly irregular; members imbricate. Corolla present; 5; including greatly reduced members, or without greatly reduced members; polypetalous. Petals imbricate; imbricate-ascending. The androecium comprising 4 members; members all free of one another; members all more or less equal in length; comprising only fertile stamens. Fertile stamens 4. Anthers attached at the base of the connective (shorter than the filaments, directed inwards at ninety degrees); dehiscing via pores or short slits. Ovary sessile or subsessile; free. Stigma not dilated. Ovules few.
Fruit, seed and seedling. Fruit still unknown?; not noticeably winged.
Transverse section of lamina. Druses absent from the mesophyll. Mesophyll secretory cavities absent. Adaxial hypodermis present. Leaf girders common (the veins transcurrent). 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 present. Cassieae-type leaf pseudo-glands present. Expanded and embedded hair-feet absent. Basally bent hairs present. Adaxial: Adaxial interveinal epidermal cell walls straight in optical section; conspicuously pitted; thick. Stomata 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; medium-thick.
Species number and distribution. 1 species (A. glabrifolium). Amazonian Brazil.
Miscellaneous. Illustrations: • A. glabrifolium: Dwyer, Ann. Mis. Bot. Gard. 44 (1957).
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’.