Morphological and molecular phylogenetic studies show that there is a close relationship between Coffea and Psilanthus. In this study we reassess species relationships based on improved species sampling for Psilanthus, including P. melanocarpus, a species that shares morpho-taxonomic characters of both genera. Analyses are performed using parsimony and Bayesian inference, on sequence data from four plastid regions [trnL-F intron, trnL-F IGS, rpl16 intron and accD-psa1 intergenic spacer (IGS)] and the internal transcribed spacer (ITS) region of nuclear ribosomal DNA (ITS 1/5.8S/ITS 2). Several major lineages with geographical coherence, as identified in previous studies based on smaller and larger data sets, are supported. Our results also confirm previous studies showing that the level of sequence divergence between Coffea and Psilanthus species is negligible, particularly given the much longer branch lengths separating other genera of tribe Coffeeae. There are strong indications that neither Psilanthus nor Coffea is monophyletic. Psilanthus melanocarpus is nested with the Coffea-Psilanthus clade, which means that there is only one critical difference between Coffea and Psilanthus; the former has a long-emergent style and the latter a short, included style. Based on these new data, in addition to other systematically informative evidence from a broad range of studies, and especially morphology, Psilanthus is subsumed into Coffea. This decision increases the number of species in Coffea from 104 to 124, extends the distribution to tropical Asia and Australasia and broadens the morphological characterization of the genus. The implications for understanding the evolutionary history of Coffea are discussed. A group of closely related species is informally named the 'Coffea liberica alliance'.

Summary• Efforts are currently underway to establish a standard DNA barcode region for fungi; we tested the utility of the internal transcribed spacer (ITS) of nuclear ribosomal DNA for DNA barcoding in lichen-forming fungi by sampling diverse species across eight orders.• Amplification of the ITS region (ITS1-5.8S-ITS2) was conducted for 351 samples, encompassing 107, 55 and 28 species, genera and families, respectively, of lichenized fungi. We assessed the ability of the entire ITS vs the ITS2 alone to discriminate between species in a taxonomic dataset (members of the genus Usnea) and a floristic dataset.• In the floristic dataset, 96.3% of sequenced samples could be assigned to the correct species using ITS or ITS2; a barcode gap for ITS is present in 92.1% of species. Although fewer species have a barcode gap in the taxonomic dataset (73.3% with ITS and 68.8% with ITS2), up to 94.1% of samples were assigned to the correct species using BLAST.• While discrimination between the most closely related species will remain challenging, our results demonstrate the potential to identify a high percentage of specimens to the correct species, and the remainder to the correct genus, when using DNA barcoding in a floristic context.

Recent studies on the circumscription of the tribe Coffeeae (Rubiaceae) revealed a weakly supported clade containing Tricalysia A. Rich. and the allied genera Argocoffeopsis Lebrun, Calycosiphonia Pierre ex Robbr., Belonophora Hook. f., Diplospora DC., Discospermum Dalzell, Nostolachma T. Durand, and Xantonnea Pierre ex Pit. The phylogenetic relationships of Tricalysia and these allied taxa are investigated further using sequence data from four plastid regions (trnL-F intron and intergenic spacer, rpL16 intron, accD-psa1 intergenic spacer, and PetD). Our results demonstrate that Tricalysia sensu Robbrecht is not monophyletic. The genus name Tricalysia should be restricted to taxa from subgenus Tricalysia; subgenus Empogona (Hook. f.) Robbr. is sister to the genus Diplospora and is recognized at the generic level. The 34 necessary new combinations for Empogona Hook. f. are provided: E. acidophylla (Robbr.

Internal transcribed spacer (ITS) ribosomal DNA sequence data were generated for 80 of the c. 200 species of Isonandreae and were added to data from African and Neotropical representatives in subfamily Sapotoideae and outgroups in Sapotaceae. Bayesian dating and ancestral area reconstruction indicated that Isonandreae are derived from within an African grade. Multiple Australasian species or lineages are derived from Sundanian lineages in South-East Asia with stem ages originating from the late Oligocene. Sri Lankan and Indian lineages are also derived from Sundanian lineages. Our results are consistent with migration from Africa into Sundania followed by numerous over-water dispersal events across Wallace's Line into Australasia and migration from Sundania to the Indian subcontinent. Pleistocene speciation indicates that sea-level changes during that epoch could have been responsible for some species diversification in Sundania.

Both lineages of Madagascan Ixora exhibit morphological innovations that are rare throughout the rest of the genus, including a trend towards pauciflorous inflorescences and a trend towards extreme corolla tube length, suggesting that the same ecological and selective pressures are acting upon taxa from both Madagascan lineages. Novel ecological opportunities resulting from climate-induced habitat fragmentation and corolla tube length diversification are likely to have facilitated species radiation on Madagascar.