Format: ORAL

Ana Paula Fortuna-Perez1, Bente B. Klitgaard2

1 Universidade Estadual Paulista, Botucatu, São Paulo, Brazil 2 Royal Botanic Gardens, Kew, United Kingdom

Dalbergioid legumes form a mostly pantropical clade containing 46 genera and about 1,370 species, of which more than half belong in four big genera: Adesmia, Aeschynomene, Dalbergia, and Machaerium. The Dalbergioid legumes encompass three lineages composed of the Adesmia, Pterocarpus and Dalbergia clades. The Amorpheae clade, resolved as sister to the Dalbergioid clade, includes eight genera of shrubs usually with paripinnate leaves, and predominantly North American. The genera form two subclades, the Daleoids and the Amorphoids. The Amorpheae clade is characterised by loss of the papilionaceous flower several times in its evolutionary history, especially in the Amorphoid subclade. This loss also occurs within the Dalbergioid clade, specially within the Pterocarpus clade. Additional to the genus Acosmium (moved to the Pterocarpus clade), the newly described Maraniona, and the reestablishment of the genera Steinbachiella and Ctenodon, recent systematic studies on Dalbergioid legumes have elucidated infrageneric relationships in the genera Aeschynomene (now excluding Ctenodon), Dalbergia, Pterocarpus, Adesmia, Nissolia (now encompassing Chaetocalyx), Zornia and Stylosanthes. Studies on floral ontogeny in the Dalbergioid clade have highlighted interesting data. In species of the Adesmia clade genera, variations are observed in the papilionaceous flowers where suppressions, abortions, reduction and/or acquisition of floral parts occur. And, other phylogenomic, anatomical and morphological studies are increasing our understanding of many new traits in the Dalbergioid clade. Belonging to Dalbergioid legumes are a wide range of economically important species and their crop wild relatives, the best known being Arachis hypogea L. (peanut), Dalbergia spp. (rosewoods), and Stylosanthes spp. (forage). However, additional genera include tree species with sought after timber. Ensuring that evolutionary relationships and taxonomy are well-understood, provide prerequisites for conservation actions for threatened tree species; and thus gives plant systematists an an even more important role to play.