Anna Luiza Ilkiu-Borges

World checklist of hornworts and liverworts

Abstract 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.

Habitat specialization triggers the evolution of unusual morphologies – the case of Cololejeunea stotleriana sp. nov. from Ecuador

Abstract River banks are home to unusual, morphologically highly specialized bryophyte taxa, which have been little studied. Here we describe a novel rheophilous and epiphyllous liverwort from Ecuador, Cololejeunea stotleriana, with many unusual morphological features such as robust stem, flat, triangular lobules, large rhizoids fields that are not produced near the base of each leaf, superfertility and clustered gynoecia. Because of its puzzling morphology, we used two regions of the chloroplast genome (trnK-H, trnL-F) to explore the systematic affinity of this new species. It turned out to be the second member of the subgenus Chlorolejeunea and the first record of this Asiatic subgenus from the New World. The species was found growing associated with the rare mosses Fissidens hydropogon and Lepidopilum caviusculum, both only known from their type specimens collected 150 years ago. The unusual morphological traits of Cololejeunea stotleriana are interpreted as adaptations to the harsh rheophilous and epiphyllous environment. The deviating morphology of the new species indicates that extreme morphological transformations can obscure the phylogenetic signal present in morphological data.