Towards new insights in the phylogeny of the Spermacoceclade: an integrative taxonomic approach using morphology, anatomy, ecology, and phylogeneticsreveals the new genus Leonoria

NUÑEZ FLORENTIN, M.; FLORENTIN JAVIER E; GONZALEZ, V.; SALAS, ROBERTO M.; DESSEIN, STEVEN; JANSSENS, STEVEN B.; CARDOSO, DOMINGOS

San Ignacio, Misiones

Conferencia; VIII International Rubiaceae and Gentinianales Conference; 2023

Instituto de Botánica del Nordeste

Phylogenetic inference analyses o f two nuclear and four plastid DNA markers from 82 accessions representing 19 genera o f the Spermacoce clade (Spermacoceae-Rubiaceae) confirm that the Brazilian genus Denscantia is biphyletic. By the analyses o f reproductive morphological characters, foliar morpho-anatomy and histochemical, geographical distribution ranges, and ecological niche derived from climatic space, Denscantia caldcóla is shown as a distinct lineage from the other Denscantia species, indicating its taxonomic segregation into a new monospecific genus Leonoria. Significant morphological diíferences o f Leonoria with Denscantia were found in inflorescence organization, stigma shape, fruit dehiscence, and pollen morphology. Morphoanatomical variation among leaf traits were found in epidemial cells, occurrence o f trichomes, mesophyll histochemical, and vascular organization. Analysis o f occurrence records o f 205 specimens demonstrates a clear ecological distinction between o f Denscantia s.s. and Leonoria, which is ecologically confined to limestone outcrops associated with seasonally dry forests. The current study demonstrates the importance of an integrative taxonomic approach - in which múltiple disciplines are combined - to the unravel complex taxonomic pattems within Rubiaceae. The genus Leonoria, to be newly described, is dedicated to Professor Elsa Leonor Cabral.