Is it really you,Orthotrichum acuminatum? Ascertaining a new case of intercontinental disjunction in mosses

Abstract

Intercontinental disjunct distributions are a main issue in current biogeography. Bryophytes usually have broad distribution ranges and therefore constitute an interesting subject of study in this context. During recent fieldwork in western North America and eastern Africa, we found new populations of a moss morphologically similar to Orthotrichum acuminatum. So far this species has been considered to be one of the most typical epiphytic mosses of the Mediterranean Basin. The new findings raise some puzzling questions. Do these new populations belong to cryptic species or do they belong to O. acuminatum, a species which then has a multiple‐continent disjunct range? In the latter case, how could such an intercontinental disjunction be explained? To answer these questions, an integrative study involving morphological and molecular approaches was conducted. Morphological results reveal that Californian and Ethiopian samples fall within the variability of those from the Mediterranean Basin. Similarly, phylogenetic analyses confirm the monophyly of these populations, showing that O. acuminatum is one of the few moss species with a distribution comprising the western Nearctic, the western Palaearctic and Palaeotropical eastern Africa. Pending a further genetic and phylogeographical study to support or reject the hypothesis, a process of long‐distance dispersal (LDD) is hypothesized to explain this distribution and the origin of the species is suggested to be the Mediterranean Basin, from where diaspores of the species may have migrated to California and Ethiopia. The spore release process in O. acuminatum is revisited to support the LDD hypothesis, © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2016, 180, 30–49.

Geographical structure, narrow species ranges, and Cenozoic diversification in a pantropical clade of epiphyllous leafy liverworts

“…Although intercontinentally disjunct bryophyte species often form monophyla (Heinrichs et al., ; Vigalondo et al., ), accessions from different continents are often resolved in sister clades (Heinrichs et al., ). This pattern of geographically structured phylogenetic relationships suggests gene flow and interbreeding between populations on different continents has ceased, and this may be confirmed by detailed study (Medina, Lara, Goffinet, Garilleti, & Mazimpaka, ).…”

“…Range estimation is a challenging theme in morphologically little differentiated groups of organisms and suitable to improve understanding of species diversity and evolution. Many bryophyte genera belong to these critical groups and are in need of thorough reinvestigation including integrative molecular-morphological approaches; however, to date, only a limited number of studies is available (Dong et al, 2012;Forrest, Salazar-Allen, Gudiño, Korpelainen, & Long, 2011;Hedenäs et al, 2014;Heinrichs et al, 2015;Renner et al, 2013;Vanderpoorten, Patiño, Dirkse, Blockeel, & Hedenäs, 2015;Vigalondo et al, 2016). These studies identified numerous morphologically not or weakly differentiated bryophyte species of which many have rather narrow ranges.…”

Integrative taxonomy sheds light on an old problem: theUlota crispacomplex (Orthotrichaceae, Musci)

“…For trnG , the primers used were trnGf_leu (Stech et al ., ) and trnGr (Pacak & Szweykowska‐Kulinska, ), and the PCR program included one melting step of 5 min at 94 °C, followed by 40 cycles of 30 s at 94 °C, 40 s at 52 °C and 1 min 30 s at 72 °C, and a final extension period of 8 min at 72 °C. For trnL ‐ trnF , the primers used were trnLc‐104 and trnFF‐425 (Vigalondo et al ., ). The PCR program included one melting step of 5 min at 94 °C, followed by 38 cycles of 30 s at 94 °C, 1 min at 47 °C, 30 s at 72 °C and 30 s at 94 °C, and a final extension period of 1 min at 72 °C.…”

The Early Cretaceous Apple Bay flora of Vancouver Island: a hotspot of fossil bryophyte diversity

“…Many extant mosses have intercontinental ranges; in a striking example, Orthotrichum acuminatum H. Philib., with documented occurrences in the western Nearctic, the western Palearctic, and Paleotropical eastern Africa, demonstrates that in mosses it is not impossible even for single species to have multiplecontinent disjunct ranges (Vigalondo et al 2016). Whereas the phylogenetic position of Steyermarkiella is unresolved, Alophosia is resolved as the basal-most member of Polytrichaceae in molecular phylogenetic analyses (Bell et al 2015).…”