Aim: African Melastomateae (Melastomataceae) comprise c. 185 species occurringin closed or open habitats throughout sub-Saharan Africa. We sought to reconstruct biogeographical and habitat history, and shifts in diversification rates of African Melastomateae using a well-sampled, dated molecular phylogeny.Location: Americas, sub-Saharan Africa, Madagascar, SE Asia.Taxon: Angiosperms, Melastomataceae, African Melastomateae.Methods: Phylogenetic relationships were estimated based on an extensive sampling of New and Old World Melastomateae, using two nuclear and three plastid markers. Divergence times were estimated in BEAST based on three calibration priors under Bayesian uncorrelated lognormal relaxed clock and birth-death speciation process. The dated phylogeny was used to infer the biogeographical history under a dispersal-extinction-cladogenesis model in "BioGeoBEARS". The ancestral habitat of African Melastomateae was estimated using maximum likelihood and stochastic character mapping in "Phytools" and "ape" respectively. Finally, shifts in diversification rates were tested using BAMM.

Melastomateae are the most species-rich (185 spp./13 gen.) and morphologically diverse tribe within the African Melastomataceae. In this study we present the first in-depth phylogenetic analysis of African Melastomateae using sequences generated from one nuclear (nrITS) and two plastid spacers (accD-psaI, psbK-psbL) sampling 183 accessions representing 75 African, 10 Madagascan and 7 Asian species and a broad outgroup sampling. We infer phylogenetic relationships using maximum likelihood, maximum parsimony and Bayesian approaches and propose a revised generic classification of African Melastomateae based on our molecular trees in combination with a careful reassessment of morphological variation. Our phylogenetic analyses support the monophyly of Old World Melastomateae except Dinophora which clearly falls outside Melastomateae. Asian and Madagascan endemic genera of Melastomateae are nested among the African genera. Of the African genera only two monophyletic groups, Dichaetanthera and Tristemma, are recovered in addition to the monospecific Pseudosbeckia lineage, while Antherotoma, Dissotis and Heterotis as currently circumscribed are polyphyletic. However, the subgenera and sections of these genera are mostly recovered as morphologically distinct and molecularly well-supported clades. Isomorphism versus dimorphism of the stamens is found to be an unreliable character when delimiting genera in Melastomateae. We propose the reinstatement of Argyrella and Dupineta, a new status at generic rank for Dissotis subg. Dissotidendron, a broadened circumscription of Guyonia (to include the species previously placed in Heterotis sect. Cyclostemma), and description of a new, monospecific genus Anaheterotis for the Heterotis pobeguinii lineage. Heterotis is maintained at generic rank but with a narrower circumscription in comparison to earlier treatments. We accommodate the rare Osbeckia porteresii lineage from Mt. Nimba (Guinea) within an expanded Melastomastrum. To complete our generic realignment, a total of 42 new combinations are effected at the species level and below, and a key is provided for the 12 genera presently recognised in African Melastomateae. Denser taxonomic sampling and sequencing of more loci will be needed to resolve relationships within the large clade of Dissotis s.str. and allies (including Antherotoma as well as three West African species erroneously placed in the otherwise Asian Osbeckia).

The Dissochaeta alliance (= subtribe Dissochaetinae) is a group of woody climbing taxa within tribe Dissochaeteae (Melastomataceae) and comprises 90 species mainly distributed in Southeast Asia. The circumscription of the alliance and its genera has been problematic when based on only morphological characters. With a broad sampling of relevant taxa, this study aims at a natural circumscription of and revised generic delimitation within this alliance. A molecular phylogeny based on two nuclear (nrETS, nrITS) and four chloroplast (ndhF, psbK‐psbL, rbcL, rpl16) markers confirmed the non‐monophyly of Dissochaeteae s.l. Taxa traditionally placed in Dissochaeteae are found in three lineages in distant positions within Melastomataceae. The Medinilla alliance is resolved within Sonerileae + Oxysporeae, while the monophyletic Dinophora/Ochthocharis lineage forms a polytomy with Marcetieae, Melastomateae, Microlicieae, and Rhexieae; and the well‐supported Dissochaeta alliance is sister to Cambessedesieae. Based on the molecular results, Dissochaeteae is redefined to exclude the Medinilla alliance and Dinophora/Ochthocharis. It consists of six successively branching major clades, which we treat as six genera, Pseudodissochaeta, Creochiton, Dalenia (Dissochaeta sect. Dalenia), Diplectria (Dissochaeta sect. Diplectria), Macrolenes and Dissochaeta s.str. To avoid a paraphyletic Dissochaeta, Dalenia and Diplectria are resurrected, Macrolenes is expanded to include the Dissochaeta rostrata complex, and a narrowly circumscribed Dissochaeta s.str. is adopted. A re‐investigation of morphological characters based on herbarium material provides support of newly defined taxa. Two sections for Macrolenes are newly proposed, and two sections of Dissochaeta s.str. are maintained. Important morphological traits such as habit and floral characters are discussed to show the morphological support for each delimited genus and the establishment of a new classification of the tribe.

Aim Using the extremophile genus Anabasis, which includes c. 28 succulent, xerophytic C4 species, and is widely distributed in arid regions of Northern Africa, Arabia, and Asia, we investigate biogeographical relationships between the Irano‐Turanian floristic region (ITfr) and its neighboring regions. We test whether the spread of arid and semi‐arid biomes in Eurasia coincides with the biogeography of this drought‐adapted genus, and whether the ITfr acted as source area of floristic elements for adjacent regions. Location Deserts and semi‐deserts of Northern Africa, Mediterranean, Arabia, West and Central Asia. Methods Four cpDNA markers (rpL16 intron, atpB‐rbcL, trnQ‐rps16, and ndhF‐rpL32 spacers) were sequenced for 58 accessions representing 21 Anabasis species. Phylogenetic relationships and divergence times were inferred using maximum likelihood and a time‐calibrated Bayesian approach. To document the extant distribution of Anabasis, material from 23 herbaria was surveyed resulting in 441 well‐documented collections used for the coding of eight floristic regions. Using this coded data, ancestral range was estimated using “BioGeoBEARS” under the DEC model. Results Anabasis originated during the Late Miocene and the ancestral range was probably widespread and disjunct between Western Mediterranean and the Irano‐Turanian regions. Diversification started with two divergence events at the Miocene/Pliocene boundary (5.1 and 4.5 mya) leading to Asian clade I with ITfr origin which is sister to a slightly younger Asian clade II, which originated in the Western ITfr, and a Mediterranean/North African clade with an origin in the Western Mediterranean. Main conclusions Anabasis did not follow aridification and continuously expanded its distribution area, in fact its probably wide ancestral distribution area seems to have been fragmented during the very Late Miocene and the remnant lineages then expanded into neighboring arid regions. This genus supports the role of the ITfr as source area for xerophytic elements in the Mediterranean and Central Asia.