Rui-Liang Zhu

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.

One species or at least eight? Delimitation and distribution of Frullania tamarisci (L.) Dumort. s. l. (Jungermanniopsida, Porellales) inferred from nuclear and chloroplast DNA markers.

Frullania tamarisci is usually regarded as a polymorphic, holarctic-Asian liverwort species with four allopatric subspecies [subsp. asagrayana, moniliata, nisquallensis and tamarisci]. This hypothesis is examined using a dataset including sequences of the nuclear internal transcribed spacer region and the plastid trnL-trnF and atpB-rbcL regions of 88 accessions of F. tamarisci and putatively related taxa. Maximum parsimony and maximum likelihood analyses indicate the presence of at least eight main lineages within F. tamarisci s. l. The long branches leading to the tip nodes of the different F. tamarisci s. l. clades and their partly sympatric distribution reinforce species rank. Within F. tamarisci s. l. we recognize the Asian F. moniliata, the western North American F. californica and F. nisquallensis, the eastern North American F. asagrayana, the eastern North American-European F. tamarisci s. str., the Macaronesian F. sergiae, and two newly identified European lineages assigned to as F. calcarifera and F. tamarisci var. azorica. The considerable sequence differences are not reflected in conspicuous morphological disparities, rendering F. tamarisci s. l. the most explicit example of a complex of semi-cryptic and cryptic liverwort species. The temperate Frullania clades of this study likely went through recent extinction and expansion processes as indicated by the bottleneck pattern of genetic diversity. Species from tropical regions or regions with an Atlantic climate usually contain several geographical lineages. Our findings support frequent short-distance migration, rare successful long-distance dispersal events, extinction and recolonization as an explanation for the range formation in these Frullania species.

Formalizing morphologically cryptic biological entities: New insights from DNA taxonomy, hybridization, and biogeography in the leafy liverwort Porella platyphylla (Jungermanniopsida, Porellales)

PREMISE OF THE STUDY Recognition and formalization of morphologically cryptic species is a major challenge to modern taxonomy. An extreme example in this regard is the Holarctic Porella platyphylla s.l. (P. platyphylla plus P. platyphylloidea). Earlier studies demonstrated the presence of three isozyme groups and two molecular lineages. The present investigation was carried out to elucidate the molecular diversity of P. platyphylla s.l. and the distribution of its main clades, and to evaluate evidence for the presence of one vs. several species. METHODS We obtained chloroplast (atpB-rbcL, trnL-trnF) and nuclear ribosomal (ITS) DNA sequences from 101 Porella accessions (P. platyphylla s.l., P. × baueri, P. cordaeana, P. bolanderi, plus outgroup species) to estimate the phylogeny using parsimony and likelihood analyses. To facilitate the adoption of Linnean nomenclature for molecular lineages, we chose a DNA voucher as epitype. KEY RESULTS Phylogenies derived from chloroplast vs. nuclear data were congruent except for P. platyphylla s.l., including a North American lineage that was placed sister to P. cordaeana in the chloroplast DNA phylogeny but sister to the Holarctic P. platyphylla s.str. in the nuclear DNA phylogeny. European and North American accessions of P. cordaeana and P. platyphylla form sister clades. CONCLUSIONS The genetic structure of P. platyphylla s.l. reflects morphologically cryptic or near cryptic speciation into Holarctic P. platyphylla s.str. and North American P. platyphylloidea. The latter species is possibly an ancient hybrid resulting from crossings of P. cordaeana and P. platyphylla s.str. and comprises several distinct molecular entities.

Liverworts and Hornworts of Thailand: An Updated Checklist and Bryofloristic Accounts

An updated checklist of liverworts (Marchantiophyta) and hornworts (Anthocerotophyta) of Thailand is presented. The checklist is based on published literature and some recent collections. The liverwort and hornwort flora of Thailand consists of 386 species belonging to 90 genera in 37 families. The largest family is Lejeuneaceae (123 spp., 25 genera). The genera with over ten species are Cololejeunea (38 spp.), Plagiochila (37 spp.), Frullania (37 spp.), Bazzania (34 spp.), and Radula (21 spp.). Sixteen species are known only from Thailand, but no genera are endemic to the country. A new name (Cololejeunea gradsteinii M.J. Lai & R.L. Zhu, nom. nov.) and a new combination (Heteroscyphus inflatus (Steph.) S.C. Srivast. & A. Srivast. var. fragilissimus (N. Kitag.) M.J. Lai & R.L. Zhu, comb, nova) are proposed. Eleven species are reported for Thailand for the first time. Vegetation and bryofloristic accounts of Thailand are also discussed.

Phylogeny of the leafy liverwort Ptilidium: Cryptic speciation and shared haplotypes between the Northern and Southern Hemispheres

The small, phylogenetically isolated liverwort genus Ptilidium has been regarded as of cool-Gondwanic origin with the bipolar, terrestrial Ptilidium ciliare giving rise to the Northern Hemisphere epiphytes Ptilidium pulcherrimum and Ptilidium californicum. This hypothesis is examined using a dataset including three chloroplast DNA regions from 134 Ptilidium accessions and one accession each of its closest relatives Trichocoleopsis and Neotrichocolea. Maximum likelihood and parsimony analyses point to a close relationship between P. ciliare and P. pulcherrimum, whereas P. californicum is placed sister to the remainder of the genus, separated by a long branch. Haplotype analysis and our phylogeny indicate the presence of Southern Hemisphere haplotypes of P. ciliare in the Northern Hemisphere, and shared haplotypes of P. ciliare and P. pulcherrimum between Europe and North America. Based on our findings, we reject the Gondwana-scenario and propose recent long distance dispersal as an explanation for the bipolar disjunct range. Ptilidium ciliare is resolved as paraphyletic with P. pulcherrimum nested within it. An isolated Ptilidium lineage with the morphology of P. ciliare from the Himalaya region likely represents a hitherto unrecognized cryptic species. Ptilidium pulcherrimum splits into a Japanese clade and a clade with accessions from Europe and North America.

Evidence for Rampant Homoplasy in the Phylogeny of the Epiphyllous Liverwort Genus Cololejeunea (Lejeuneaceae)

Abstract Rampant homoplasy can be a major challenge in the classification of land plants that have limited morphological differences and/or ecological diversity, such as liverworts and mosses. Here we present the first comprehensive molecular phylogeny of the derived liverwort genus Cololejeunea and its close relatives. We used three markers (trnL—F, rbcL, and nrITS) and 116 accessions representing the geographic range as well as the morphological diversity of this predominantly epiphyllous genus. The molecular data support three major lineages: Colura, Myriocoleopsis, and Cololejeunea. Myriocoleopsis species were resolved in a clade with Cololejeunea minutissima. Aphanolejeunea and Chondriolejeunea were both resolved as putative monophyletic groups, and nested in the Cololejeunea clade. Cololejeunea angustiflora was found to be sister to the clade comprising the remaining Cololejeunea species. Currently accepted subgenera of Cololejeunea were paraphyletic or polyphyletic. Six out of 30 species with multiple accessions were not supported as natural taxa. The current classifications of Cololejeunea have been influenced by frequent homoplasy of morphological characters and do not accurately reflect species relationships. A new classification for this genus is outlined. Our data did not provide evidence for ancient vicariance events where major clades and continents are associated, instead some evidence was recovered for recent intercontinental species range expansion.

Liverworts and Hornworts of Taiwan: An Updated Checklist and Floristic Accounts

An updated checklist of the liverworts (Marchantiophyta) and hornworts (Anthocerotophyta) of Taiwan is presented. Based on published records, the present checklist includes 512 species of liverworts belonging to 116 genera in 52 families and 19 species of hornworts belonging to six genera in three families. Lejeuneaceae with 121 spp. in 24 genera is the largest family, containing ca. 23% of the total number of species. Genera with more than ten species are Frullanici (49 spp.), Cololejeunea (41 spp.), Plagiochila (36 spp.), Radula (26 spp.), Lejeunea (25 spp.), Bazzania (18 spp.), Scapania (18 spp.), Solenostoma (17 spp.), Riccardia (15 spp.), Porella (12 spp.) and Heteroscyphus (11 spp.). Twenty-five taxa are hitherto known only from Taiwan. Forty-seven formerly recorded species are dubious and excluded from this checklist. Chiloscyphus engelii R.L. Zhu & M.J. Lai nom. nov. as well as Folioceros verruculosus (J. Haseg.) R.L. Zhu & M.J. Lai comb. nova, Lejeunea barbata (Herzog) R.L. Zhu & M.J. Lai, comb. nova and Lejeunea luzonensis (Steph.) R.L. Zhu & M.J. Lai, comb. nova are proposed. Cololejeunea peraffinis fo. corticola (Benedix ex Herzog) S.H. Lin is treated as a new synonym of Cololejeunea peraffinis (Schiffn.) Schiffn.

Leucolejeunea, a new synonym of Cheilolejeunea (Lejeuneaceae), with special reference to new combinations and nomenclature

Abstract The pantropical genus Leucolejeunea is proposed as a new synonym of Cheilolejeunea (Lejeuneaceae). Eleven species in Leucolejeunea are moved to Cheilolejeunea. Nine new combinations and two new changes in nomenclature in Cheilolejeunea are proposed.

Drepanolejeunea laciniata (Lejeuneaceae ), a new species from northern Thailand

Abstract Drepanolejeunea laciniata Qiong He et R.L. Zhu sp. nov., is described and illustrated from Doi Inthanon National Park, Chom Thong District, Chiang Mai Province, northern Thailand. It is similar to Drepanolejeunea pulla (Mitt.) Grolle and D. erecta (Steph.) Grolle, but differs mainly in its large leaf lobule that is 1/2–2/3 as long as the leaf lobe, the free lateral lobular margin proximal to the notch bordered by 9–13 rectangular cells, the obovate perianth with dense apical laciniae, and usual presence of median ocelli in the leaf lobe.

Phylogenetic position of Oryzolejeunea (Lejeuneaceae, Marchantiophyta): Evidence from molecular markers and morphology

The systematic position of the small neotropical genus Oryzolejeunea (three spp.) has long been controversial. Phylogenetic analyses of molecular data for the present study using DNA markers (trnL, psbA, and a nuclear ribosomal internal transcribed spacer [nrITS] region) shows that the genus is nested in Lejeunea. The results not only reveal the phylogenetic position of Oryzolejeunea for the first time, but also challenge the taxonomic value of the proximal hyaline papilla as a key feature in Lejeunea. The present study shows the urgent need for a reassessment of the perimeters of the genus Lejeunea and its infrageneric classification. Three new combinations, namely Lejeunea saccatiloba, Lejeunea grolleana, and Lejeunea venezuelana, are proposed.