The largest genus within the Phyllanthaceae family is a group called Phyllanthus L. Recent studies have shown, that Phyllanthus is paraphyletic with the genera Glochidion, Breynia and Synostemon... Show moreThe largest genus within the Phyllanthaceae family is a group called Phyllanthus L. Recent studies have shown, that Phyllanthus is paraphyletic with the genera Glochidion, Breynia and Synostemon nested within it. In this thesis, I study the evolution and systematics of Phyllanthus and how to solve the apparent paraphyly. First we explore past morphological subgroups to come to a subdivision, which was tested using molecular phylogenetics. Several species of Phyllanthus are also used in traditional medicine and by utilizing the living collections of the Hortus botanicus Leiden, we tested for antibacterial and antifungal bioactivity. The phylogeny resulting from this study is used to study the historical biogeography and diversification of the tribe and to propose a new classification where Phyllanthus is separated into several smaller genera. Show less
The majority of tribe Phyllantheae (Phyllanthaceae) is currently placed in the paraphyletic genus Phyllanthus and discussions have persisted on how to resolve this issue. Here, we split Phyllanthus... Show moreThe majority of tribe Phyllantheae (Phyllanthaceae) is currently placed in the paraphyletic genus Phyllanthus and discussions have persisted on how to resolve this issue. Here, we split Phyllanthus into ten monophyletic genera, which are all reinstatements of former genera, but with changes made to the circumscription and constituent species of each group. The genera Breynia, Glochidion and Synostemon were recently found to be nested within Phyllanthus and discussions ensued whether or not to subsume everything into Phyllanthus s.l. Instead of combining all these genera, we here implement the solution of splitting Phyllanthus into strictly monophyletic genera to ensure that the classification is consistent with the latest phylogenetic results. The new classification is based on a phylogenetic framework combined with differences in habit, branching type, floral, fruit and pollen morphology. With this new division of the genus Phyllanthus, tribe Phyllantheae will consist of the following 18 genera: Breynia, Cathetus, Cicca, Dendrophyllanthus, Emblica, Flueggea, Glochidion, Heterosavia, Kirganelia, Lingelsheimia, Lysiandra, Margaritaria, Moeroris, Nellica, Nymphanthus, Phyllanthus, Plagiocladus and Synostemon. As a result of the reinstated genera, five new names for illegitimate combinations or previous overlooked nomenclatural anomalies and 645 new combinations are proposed. Several keys are provided to distinguish the reinstated genera. Full species lists are given for the reinstated genera treated here except for Breynia, Synostemon and Glochidion. Show less
The genus Phyllanthus is paraphyletic as currently circumscribed, with the genera Breynia, Glochidion and Synostemon nested within it. A phylogeny based on nuclear (ITS, PHYC) and chloroplast (matK, .Show moreThe genus Phyllanthus is paraphyletic as currently circumscribed, with the genera Breynia, Glochidion and Synostemon nested within it. A phylogeny based on nuclear (ITS, PHYC) and chloroplast (matK, accD-psaI, trnS-trnG) markers is presented, including 18/18 subgenera and 53/70 sections. Differences in habit, branching type, floral and fruit characters are discussed, and we find indications for shifts in pollination and dispersal strategies possibly underlying the convergent evolution of these characters in multiple clades. Several taxonomic issues were found in the subgeneric classification of Phyllanthus that will require new transfers and rank changes. Phyllanthus subg. Anesonemoides, subg. Conami, subg. Emblica, subg. Gomphidium, subg. Kirganelia and subg. Phyllanthus are polyphyletic, and several sections appear to be paraphyletic (e.g., P. sect. Anisonema, sect. Emblicastrum, sect. Pseudoactephila, sect. Swartziani, and sect. Xylophylla); P. subg. Phyllanthodendron is furthermore paraphyletic with the genus Glochidion nested within. To create a classification of tribe Phyllantheae that comprises exclusively monophyletic taxa, it is necessary to treat several clades at the same taxonomic rank as the genera Breynia, Glochidion and Synostemon. Since combining all genera would lead to one giant heterogeneous genus that is difficult to define, we recommend dividing Phyllanthus into several monophyletic genera, which have previously been recognized and often possess diagnostic (combinations of) morphological characters. This new classification is forthcoming. Show less
Molecular phylogenetic studies focused on the genus Phyllanthus L. (Phyllanthaceae) showed that Sauropus Blume (including Synostemon F.Muell.) and its related genera Breynia J.R.Forst. & G... Show moreMolecular phylogenetic studies focused on the genus Phyllanthus L. (Phyllanthaceae) showed that Sauropus Blume (including Synostemon F.Muell.) and its related genera Breynia J.R.Forst. & G.Forst. and Glochidion J.R.Forst. & G.Forst. should be united with Phyllanthus to create a monophyletic genus. The relationships within Sauropus and its relationship with Breynia were studied to test/corroborate such a broad definition of Phyllanthus. The molecular phylogenetic analyses show that Sauropus in the broad sense is composed of two distinct groups, the former Australian Synostemon and the Southeast Asian Sauropus in the strict sense with the monophyletic Breynia embedded in the latter. As the phylogeny of the species rich Phyllanthus is still far from completed and the results here strongly support the distinction of monophyletic groups such as Glochidion, former Synostemon, and Sauropus/Breynia. These genera are recognisable, while union with Phyllanthus (suggested by Hoffmann and co-authors in 2006) will turn the latter into an unrecognisable monolithic giant of a genus. It is a much better strategy to use the complete phylogeny of Phyllanthus to render it into smaller, monophyletic genera that can be characterized. The present study shows Synostemon has to be recognised again on generic level. Breynia, the older name, is nested within Sauropus, leading us to transfer the latter to Breynia. Within this broadened Breynia, two subgenera and two sections are distinguished, subgenus Sauropus and subgenus Breynia with section Cryptogynium and section Breynia under the latter. Show less
