Popper’s falsificationism is frequently referred to as a general normative reference system in phylogenetics. Referring to falsificationism, phylogeneticists have made four central claims, including that frequency probabilities (1) cannot be used for inferring degrees of corroboration and (2) cannot be used in phylogenetics because phylogeny is a unique process, (3) likelihood methods represent verificationist approaches, and (4) the congruence test is a Popperian test. However, these claims are inconsistent with Popper’s theory. Moreover, phylogeneticists have proposed four strategies for dealing with the unfalsifiability of cladograms, including (1) interpreting re-interpretations of putative synapomorphy as homoplasy as Popperian ad hoc manoeuvres, (2) decoupling corroboration from falsification, (3) interpreting the tree with the highest likelihood as the most corroborated tree, and (4) interpreting tree hypotheses as Popperian probabilistic hypotheses that do not have to be falsifiable. These strategies are also inconsistent with Popper’s theory. Four fundamental problems and a problem with Popper’s formula for measuring degree of corroboration demonstrate that Popper’s theory does not live up to its own claims. Moreover, neither historical nor experimental sciences can be conducted in a way that is consistent with the principles of falsificationism. Therefore, phylogeneticists should stop referring to falsificationism when defending a specific methodological position.

For more than 75 years, the Lord Howe Island moss Spiridens muelleri Hampe has been considered conspecific with Spiridens vieillardii Schimp., originally described from New Caledonia. A comparison of morphological characters not previously considered, along with DNA sequences from three chloroplast loci (trnL–trnF, rps4–trnS, rpl32–trnL) and ITS-2 of nuclear rDNA, supports their recognition as separate species.

Biogeography of Sideroxylon (Sapotoideae) and whether the satellite genera Argania and Spiniluma merit recognition are revisited. The hypothesis of an African origin with a subsequent migration to Central America via Europe and the North Atlantic landbridge is challenged. We analysed 58 accessions of trnH-psbA and ITS sequences in a fossil-calibrated, relaxed lognormal clock model with BEAST for phylogenetic and biogeographic inference. Argania spinosa (L.) Skeels from Morocco must be united with Sideroxylon, whereas S. discolor Radcl.-Sm. and S. oxyacanthum Baill. belong to subfamily Chrysophylloideae and may be recognised as Spiniluma. The divergence time estimate suggests that Sideroxylon originated and first diversified in Central America 56.3–52.2 million years ago, contemporaneous with the landbridge, but an archipelago of islands and the Tethys Seaway halted eastward expansion to Africa until c. 20 million years ago, i.e. 25 million years after establishment in Africa. Range expansion of Sideroxylon was therefore not powered by the landbridge, and a long-distance dispersal from Central America to Africa is proposed. The establishment of the Gomphotherium landbridge between Africa and Eurasia at 19 million years ago provided a land-migration route to Europe and Asia, which is reconcilable with the extension of Xantolis into Asia. Sideroxylon has colonised Socotra by over-water dispersal in the Gulf of Aden, Macaronesia, Madagascar and the Mascarene Islands.

The Swan Coastal Plain of south-west Western Australia has been extensively cleared since European settlement, with the fertile Pinjarra Plain land system preferentially cleared for grazing; what remains of the native vegetation is of high conservation value despite being highly fragmented and often degraded. The following six taxa of Synaphea R.Br. (Proteaceae), with conservation status corresponding to IUCN Red List categories Threatened and Data Deficient, are restricted to vegetation remnants in this region: S. stenoloba A.S.George, S. odocoileops A.S.George, S. sp. Pinjarra (R. Davis 6578), S. sp. Fairbridge Farm (D. Papenfus 696), S. sp. Pinjarra Plain (A.S. George 17182) and S. sp. Serpentine (G.R. Brand 103). Taxonomic boundaries among these morphologically similar taxa of Synaphea were investigated using morphometric analyses based on characters of leaves, inflorescences, flowers and fruits. Results allow the circumscription of the four informally named taxa from this complex, which will enable their formal description in a subsequent publication. They also provide support for several morphologically closely related taxa, including the provisional distinction of S. sp. Udumung (A.S. George 17058) from close ally S. decorticans Lindl. Two described species (S. odocoileops and S. stenoloba) and several anomalous specimens could not be adequately resolved in these analyses, and further investigation of their boundaries using molecular markers is required.

Micromorphology of seeds and pollen of Orobanche alsatica, O. bartlingii and O. mayeri, the central European representatives of the O. alsatica aggregate (Orobanchaceae) was investigated on the basis of 32 samples from 18 localities in Poland, Slovakia, Czech Republic, Austria, Bosnia and Herzegovina, and Russia. Concerning seeds, the best taxonomic character is a narrow trough on external sides of radial walls of cells of the seed wall, which is always present and continuous in O. bartlingii, mostly absent in O. mayeri, and mostly present solely at wall segment junctions (vertices) in O. alsatica (individuals parasitising Peucedanum spp.; continuous in parasites of Seseli osseum). As for pollen, the exine sculpture is verrucate in O. mayeri, granulate in O. bartlingii, and granulate to scabrate in O. alsatica. O. alsatica parasitising Peucedanum spp. and Seseli osseum (host-related morphotypes) differ in seed shape, ornamentation and wall-perforation diameter. Variability of seed and pollen characters is high, and identical morphologies occur among the investigated species. The variation coefficient is too strongly correlated with the sample size to be a reliable estimator the taxonomic value of a character. Differences in seed and pollen sculpture, hosts and ecological preferences confirm the separation of the three examined taxa at species level.