A multidiscyplinary study of Diodia s.l. (Spermacoceae-Rubiaceae)

CABAÑA, F.A.A.; GALATI, B.; SALAS, R.M.; CABRAL, E.L.

Salvador, Bahia

Conferencia; VI International Rubiaceae and Gentianales Conference; 2014

VI Conference Organizing Committee, Universidade Federal da Paraíba, Brasil

Diodia s.l. is one of the most conflictive taxa beloning to the Spermacoce clade. For decades, this taxon consisted in species with indehiscent or schizocarpic fruits, though remarkable morphologycal variations. Currently, it is considered a polyphyletic group with approximately 120 species named here as Diodia s.l. It includes five species of Diodia s.s., and all those species described under Diodia and transferred to other related genera (Borreria, Diodella, Galianthe, Mitracarpus, and Spermacoce). The aim of this work is to establish the taxonomic status of some entities based on a multidisciplinary approach and determine its possible phylogenetic relationship. We analized cytogenetic, morpho-anatomical, palynologycal, and embryologycal features of the species principally of the Americas. In addition we performed a taxonomic study of the most confictive and less known taxa of Diodia s.l. As the most important results of this work, we performed an update of the 30 names published as Diodia. Also, we proposed a new taxonomic circunscription for some species of Diodia suppported by pollen and seed morphology. The morphological and embrylogycal yielded very promising to the taxonomic of Diodia and other closest taxa of Spermacoce clade. Moreover, the fruit was reaffirmed as an important feature in some genera of this group (i.e. Diodella).