A new key to the genera of liverworts of Colombia

A key is presented to 130 liverwort genera recorded from Colombia. Some genera found in neighboring countries, but not yet in Colombia, are also included in the ke

A new key to the genera of liverworts of Colombia

A key is presented to 130 liverwort genera recorded from Colombia. Some genera found in neighboring countries, but not yet in Colombia, are also included in the ke

Cheilolejeunea schiavoneana (Marchantiophyta: Lejeuneaceae), una nueva especie de Colombia

We describe the new liverwort species Cheilolejeunea schiavoneana M.E.Reiner & Gradst. from submontane rainforest in the Western Cordillera of Colombia. The new species is related to C. adnata (C. sect. Cheilolejeunea) but differs by larger plant, leaf and underleaf size, robust stems, a 5-6 cells wide ventral merophyte, abundance of microphyllous branches, and vegetative reproduction by caducous leaf lobes produced on flagelliform shoots. The latter feature is characteristic of the genus Rectolejeunea and its presence in Cheilolejeunea is apparently a case of parallel evolution. The discovery of C. schiavoneana adds a further endemic taxon to the rich flora of the Colombian Western Cordillera. KeyCheilolejeunea schiavoneana (Marchantiophyta: Lejeuneaceae), una nueva especie de Colombia. Se describe la nueva especie Cheilolejeunea schiavoneana M.E.Reiner & Gradst., coleccionada en selva submontana de la Cordillera Occidental de Colombia. Este nuevo taxon está relacionado con C. adnata (C. sección Cheilolejeunea) pero difiere en el mayor tamaño de las plantas, hojas y anfigastrios, el ancho del merofito ventral (de 5-6 células), la abundancia de ramas microfilas, y la reproducción vegetativa por medio de lobos caducos producidos en tallos flagelíferos. Esta última propiedad es característica del género Rectolejeunea, y su presencia en Cheilolejeunea es aparentemente debida a evolución paralela. El descubrimiento de C. schiavoneana agrega otro taxon endémico a la gran diversidad de la flora en la Cordillera Occidental de Colombia

Geographical range in liverworts: does sex really matter?

AimWhy some species exhibit larger geographical ranges than others remains a fundamental, but largely unanswered, question in ecology and biogeography. In plants, a relationship between range size and mating system was proposed over a century ago and subsequently formalized in Baker's Law. Here, we take advantage of the extensive variation in sexual systems of liverworts to test the hypothesis that dioecious species compensate for limited fertilization by producing vegetative propagules more commonly than monoecious species. As spores are assumed to contribute to random long-distance dispersal, whereas vegetative propagules contribute to colony maintenance and frequent short-distance dispersal, we further test the hypothesis that monoecious species exhibit larger geographical ranges than dioecious ones.LocationWorldwide.MethodsWe used comparative phylogenetic methods to assess the correlation between range size and life history traits related to dispersal, including mating systems, spore size and production of specialized vegetative propagules.ResultsNo significant correlation was found between dioecy and production of vegetative propagules. However, production of vegetative propagules is correlated with the size of geographical ranges across the liverwort tree of life, whereas sexuality and spores size are not. Moreover, variation in sexual systems did not have an influence on the correlation between geographical range and production of asexual propagules.Main conclusionsOur results challenge the long-held notion that spores, and not vegetative propagules, are involved in long-distance dispersal. Asexual reproduction seems to play a major role in shaping the global distribution patterns of liverworts, so that monoecious species do not tend to display, on average, broader distribution ranges than dioecious ones. Our results call for further investigation on the spatial genetic structure of bryophyte populations at different geographical scales depending on their mating systems to assess the dispersal capacities of spores and asexual propagules and determine their contribution in shaping species distribution ranges

Temperature dependence of liverwort diversification reveals a cool origin and hot hotspots

The evolutionary history underlying gradients in species richness is still subject to discussions and understanding the past niche evolution might be crucial in estimating the potential of taxa to adapt to changing environmental conditions. In this study we intend to contribute to elucidation of the evolutionary history of liverwort species richness distributions along elevational gradients at a global scale. For this purpose, we linked a comprehensive data set of genus occurrences on mountains worldwide with a time-calibrated phylogeny of liverworts and estimated mean diversification rates (DivElev) and mean ages (AgeElev) of the respective genera per elevational band. In addition, we reconstructed the ancestral temperature preferences of the genera. We found that diversification rates increase linearly with temperature, and hence decrease with elevation. This pattern is mainly driven by epiphytic genera. In contrast, overall genus age is highest at intermediate elevations where liverwort species richness peaks and decreases towards both ends of the elevational and thermal gradient. Our results further indicate that the ancestral lineages from which the extant liverwort genera descended had a preference for cool and humid habitats. We conclude that the extant liverwort species diversity accumulated over long time under these climatic conditions, which are today prevailing at mid-elevations of the world’s mountains. Subsequently, liverworts expanded their ranges from these temperate areas towards warm (with high diversification rates) and cold regions (with low diversification rates), located in contemporaneous (tropical) lowlands and high mountains, respectively. The conserved preference for temperate climates shared by the majority of liverwort lineages gives reason to the assumption that they will not be able to cope with the conditions induced by rapid climate warming, whereas the current low-elevation radiation may be less affected by climate change

A taxonomic treatment of Lejeunea discreta, l. eifrigii and l. sordida, new to peninsular Malaysia

Lejeunea discreta Lindenb., Lejeunea eifrigii Mizut. and Lejeunea sordida (Nees) Nees, reported for the first time from Peninsular Malaysia, are fully described and illustrated

An integrative taxonomic study of the genus Lethocolea (Marchantiophyta: Acrobolbaceae)

Background and aims – Lethocolea (Acrobolbaceae) is a small liverwort genus of seven species distributed in temperate regions of the Southern Hemisphere and on tropical mountains. The taxonomic history of the genus has been chaotic, the species were described under many different names and have been distinguished mainly based on geography. Here, we undertook a taxonomic revision of the genus based on a reassessment of morphological characters and a molecular analysis. Material and methods – Type material and additional collections from 17 herbaria were examined in the morphological study. Sequences of the rps4 chloroplast region and maximum likelihood analyses were used to reconstruct the phylogeny. Key results and conclusions – Two fully supported clades were resolved within Lethocolea lending support to the recognition of two subgenera, subgen. Lethocolea and subgen. Symphyomitra. Lethocolea congesta from Africa, and L. glossophylla and L. radicosa from America exhibited considerable morphological overlap and were not distinguishable based on rps4 sequences. The latter two species are reduced into synonymy with L. congesta, whose range spans across Africa, the Neotropics and southern South America. In Australasia, where only one species, L. pansa, is recognized, two morphotypes were found. The first one, with a smooth cuticle, wingless gemmae, and leaf cells without trigones, is identical to the type of L. pansa and occurs in Australia and New Zealand. In addition, the species is newly reported from South Africa. The second morphotype has a papillose cuticle, winged gemmae, and leaf cells with distinct trigones, and is assigned to L. javanica, which ranges across Australasia and furthermore occurs in Java and India. The recognition of these two species is supported by molecular analysis. Altogether, we recognize four species within Lethocolea, which are thoroughly described, illustrated, and keyed. We present 12 new lectotypifications

Increased diversification rates follow shifts to bisexuality in liverworts

Shifts in sexual systems are one of the key drivers of species diversification. In contrast to angiosperms, unisexuality prevails in bryophytes. Here, we test the hypotheses that bisexuality evolved from an ancestral unisexual condition and is a key innovation in liverworts. We investigate whether shifts in sexual systems influence diversification using hidden state speciation and extinction analysis (HiSSE). This new method compares the effects of the variable of interest to the best-fitting latent variable, yielding robust and conservative tests. We find that the transitions in sexual systems are significantly biased toward unisexuality, even though bisexuality is coupled with increased diversification. Sexual systems are strongly conserved deep within the liverwort tree but become much more labile toward the present. Bisexuality appears to be a key innovation in liverworts. Its effects on diversification are presumably mediated by the interplay of high fertilization rates, massive spore production and long-distance dispersal, which may separately or together have facilitated liverwort speciation, suppressed their extinction, or both. Importantly, shifts in liverwort sexual systems have the opposite effect when compared to angiosperms, leading to contrasting diversification patterns between the two groups. The high prevalence of unisexuality among liverworts suggests, however, a strong selection for sexual dimorphism

World checklist of hornworts and liverworts

A working checklist of accepted taxa worldwide is vital in achieving the goal of developing an online flora of all known plants by 2020 as part of the Global Strategy for Plant Conservation. We here present the first-ever worldwide checklist for liverworts (Marchantiophyta) and hornworts (Anthocerotophyta) that includes 7486 species in 398 genera representing 92 families from the two phyla. The checklist has far reaching implications and applications, including providing a valuable tool for taxonomists and systematists, analyzing phytogeographic and diversity patterns, aiding in the assessment of floristic and taxonomic knowledge, and identifying geographical gaps in our understanding of the global liverwort and hornwort flora. The checklist is derived from a working data set centralizing nomenclature, taxonomy and geography on a global scale. Prior to this effort a lack of centralization has been a major impediment for the study and analysis of species richness, conservation and systematic research at both regional and global scales. The success of this checklist, initiated in 2008, has been underpinned by its community approach involving taxonomic specialists working towards a consensus on taxonomy, nomenclature and distribution