A new generic system for the pantropical Caesalpinia group (Leguminosae)

Abstract

The Caesalpinia group is a large pantropical clade of ca. 205 species in subfamily Caesalpinioideae (Leguminosae) in which generic delimitation has been in a state of considerable flux. Here we present new phylogenetic analyses based on five plastid and one nuclear ribosomal marker, with dense taxon sampling including 172 (84%) of the species and representatives of all previously described genera in the Caesalpinia group. These analyses show that the current classification of the Caesalpinia group into 21 genera needs to be revised. Several genera (Poincianella, Erythrostemon, Cenostigma and Caesalpinia sensu Lewis, 2005) are non-monophyletic and several previously unclassified Asian species segregate into clades that merit recognition at generic rank. In addition, the near-completeness of our taxon sampling identifies three species that do not belong in any of the main clades and these are recognised as new monospecific genera. A new generic classification of the Caesalpinia group is presented including a key for the identification of genera, full generic descriptions, illustrations (drawings and photo plates of all genera), and (for most genera) the nomenclatural transfer of species to their correct genus. We recognise 26 genera, with reinstatement of two previously described genera (Biancaea Tod., Denisophytum R. Vig.), re-delimitation and expansion of several others (Moullava, Cenostigma, Libidibia and Erythrostemon), contraction of Caesalpinia s.s. and description of four new ones (Gelrebia, Paubrasilia, Hererolandia and Hultholia), and make 75 new nomenclatural combinations in this new generic system.

Global Succulent Biome phylogenetic conservatism across the pantropical Caesalpinia Group (Leguminosae)

“…Recent studies by Gagnon et al (2013Gagnon et al ( , 2016 that generated a robust phylogeny sampling all 26 genera and 75% of species, provide the opportunity to examine geo-temporal patterns of…”

O arco de violino

“…Isso teria criado grande demanda por arcos, especialmente pelo mercado asiático. Atualmente a maioria dos arcos profissionais são feitos de madeira de pau-brasil, antes Caesalpinea echinata, agora Paubrasilia echinata [6]. Embora essa espécie esteja com restrições comerciais internacionais e protegida por lei em virtude do risco de extinção [7,8], sua demanda mundial para produção de arcos é estimada em 200 m 3 anuais [9].…”

A new species of Erythrostemon (Leguminosae, Caesalpinioideae) from the western Río Balsas Depression, Mexico

“…Erythrostemon was re-circumscribed by Gagnon et al (2016). The neotropical genus currently includes a total of 31 species of woody shrubs or small to medium-sized trees.…”

“…The neotropical genus currently includes a total of 31 species of woody shrubs or small to medium-sized trees. Species distributions follow a bicentric amphitropical distribution pattern in México, Central America and the Caribbean, Brazil, Argentina, Bolivia, Chile and Paraguay (Lewis 1998; Gagnon et al 2013; Gagnon et al 2016). They grow in a wide range of habitats including seasonally dry tropical forests, caatinga vegetation, deserts, yungas-puna transition zones, and chaco-transition forests.…”

“…During a revision of Caesalpinia sensu lato in Guerrero and Michoacán, several specimens identified in herbaria as Caesalpinia hintonii Sandwith (a species recently transferred to the genus Erythrostemon , Gagnon et al 2016) proved to be morphologically distinct. Taking into account the above morphological diagnostic characters of Erythrostemon , a detailed study indicated that these specimens belong to that genus, although they do not match the description of any previously described species.…”