On the temporal inconsistencies of Linnean taxonomic ranks

The inconsistency problem in systematics refers in part to the fact that disparate taxa of identical Linnean rank are not necessarily similar or even readily comparable in any other specifiable biological feature. This shortcoming led to a ‘temporal banding’ proposal in which extant clades associated with particular taxonomic ranks would be standardized according to a universal metric: the absolute time of evolutionary origin. However, one underexplored possibility is that same‐level taxa in disparate organismal groups already might be similar (fortuitously so) in evolutionary age. In the present study, we explicitly address this possibility by reviewing published molecular inferences about the known or suspected origination dates of taxonomic genera, families, and orders in diverse organismal groups. Our findings empirically confirm that currently recognized taxa are far from temporally standardized, thereby adding support for the contention that this kind of taxonomic inconsistency should ultimately be rectified in our biological classifications. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 102 , 707–714.     

A new multiflorous species of Leymus (Poaceae: Triticeae) from western China

A new species of Leymus section Racemosus, L. pluriflorus L.B.Cai & T.L.Zhang, is described and illustrated. It grows in the eastern part of Qinghai Province and the southern part of Gansu Province, China. It most closely resembles L. crassiusculus L.B.Cai, from which it differs in having longer rachis internodes, some pedicellate spikelets, more florets per spikelet, glabrous lemmas, shorter paleas and shorter anthers. It differs from all other Chinese species taxa in Leymus with regard to the large number (8–12) of florets in its spikelets, and from all species of Leymus in adjacent countries in having three to four spikelets per node. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 159 , 343–348.     

Combining traditional morphometrics and molecular markers in cryptic taxa: towards an updated integrative taxonomic treatment for Veronica subgenus Pentasepalae (Plantaginaceae sensu APG II) in the western Mediterranean

The aim of this study was to quantify the phenotypic differences amongst the taxa included in Veronica subgenus Pentasepalae, represented in the western Mediterranean area. In combination with previously obtained data on genotypic differences, this enabled the recognition of eight taxonomic units. The delimitation of the boundaries among species and subspecies was mainly based on molecular data, whereas the best characters to discriminate taxa were selected after an accurate study of herbarium material and living populations. Such a selection was also supported by a detailed morphometric study of 30 quantitative leaf traits in 88 populations. Several morphological characters, including the length of the trichomes, length of the petiole and leaf division, were found to be robust, and could be useful in the identification of the taxa involved. As a conclusion, a key to the taxa is proposed, as well as a complete nomenclatural treatment for the group, which includes the typification of several names. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 159 , 68–87.     

Cotyledon areoles in Bobgunnia (Fabaceae: Swartzieae)

Cotyledon areoles, a seed character unique to papilionoid legumes, are reported for the first time in the legume tribe Swartzieae, an anomalous group sometimes considered to be intermediate between subfamilies Caesalpinioideae and Papilionoideae. Bobgunnia madagascariensis has a linear, slightly branched cotyledon areole on the abaxial surface of each cotyledon. Previous reports of other papilionoid seed features in this species are confirmed and extended. These highly distinctive papilionoid seed structures, and recent reports from floral ontogeny and molecular systematics which show Bobgunnia to be closely related to Swartzia and several other genera of Swartzieae, add further evidence to assertions that Swartzia seed structures are derived by simplification from a papilionoid seed, and not by retention of less specialized caesalpinioid seed features. The function and evolutionary advantage of cotyledon areoles are unknown and need investigation. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 159 , 287–291.     

Molecular and morphological variation of rare endemic oncocyclus irises (Iridaceae) of Lebanon

Oncocyclus irises endemic to Lebanon form a complex of three closely related taxa replacing each other over short geographical distances in a linear habitat. In order to characterize the appropriate taxonomic levels and to assess their conservation status, we investigated patterns of phenotypic variability and the partitioning of genetic variation within and among populations using random amplified polymorphic DNA (RAPD) markers. Multivariate analysis (principal components analysis and multiple correspondence analysis), based on 16 quantitative and six qualitative characters, revealed no separation between populations or taxa. Moreover, no morphological character could be used to define clear boundaries between populations/taxa. The genetic characterization revealed high levels of polymorphism and diversity (H_s). Principal components analysis showed population delimitations, but no groupings reflecting the currently defined taxa could be identified. Both morphological and genetic data showed that Lebanese oncocyclus irises could not be fitted into clear taxonomic boundaries. Consequences for conservation are discussed. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 159 , 123–135.     

Phylogeographic analyses reveal distinct lineages of the liverworts Metzgeria furcata (L.) Dumort. and Metzgeria conjugata Lindb. (Metzgeriaceae) in Europe and North America

Seed plant genera often exhibit intercontinental disjunctions where different species are found on different continents. Many morphologically circumscribed bryophyte species exhibit similar disjunctions. We used nucleotide sequences from the plastid and nuclear genomes to test hypotheses of phylogeography within representatives of the genus Metzgeria: Metzgeria furcata, Metzgeria conjugata, and Metzgeria myriopoda. The first two species have sexual and asexual populations, exhibit disjunctions between North America and Europe, and have been split into separate species, numerous subspecies or varieties. The third species occurs in eastern North America but is not reported from Europe. Phylogenetic analyses resolved three distinct lineages within the morphologically defined species, M. furcata: one in North America, and two in Europe. Similarly, three morphologically cryptic clades of M. conjugata were resolved by the molecular data: northern North America, Europe, and south‐eastern North America. For both species, molecular divergence among taxa occurred in the absence of morphological change. In the case of M. myriopoda, all plants from eastern North America were both morphologically uniform and genetically homogeneous (although not identical). The present study provides significant insight into a plant group with complex taxonomy, and indicates that these liverwort taxa with wide distributions, extreme sex ratios, and continental disjunctions harbor cryptic lineages. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 98 , 745–756.     

Phylogeographic analysis of the nocturnal velvet ant genus Dilophotopsis (Hymenoptera: Mutillidae) provides insights into diversification in the Nearctic deserts

Understanding the history of diversification in the North American deserts has long been a goal of biogeographers and evolutionary biologists. Although it appears that a consensus is forming regarding the patterns of diversification in the Nearctic deserts in vertebrate taxa, little work has been done exploring the historical biogeography of widespread invertebrate taxa. Before a robust model of geobiotic change in the North American deserts can be proposed, it needs to be determined whether the same historical events affected vertebrate and invertebrate taxa in the same way. We explore the phylogeographic patterns in a widespread nocturnal wasp genus Dilophotopsis using two rDNA loci, the internal transcribed spacer regions 1 and 2 (ITS1 and ITS2). We use Bayesian phylogenetic analysis and haplotype network analysis to determine whether a consistent geographic pattern exists among species and populations within Dilophotopsis. We also used molecular dating techniques to estimate divergence dates of the major phylogenetic clades. Our analyses indicates that the species‐level divergences in Dilophotopsis occurred in the Neogene, and likely were driven by mountain building during the Miocene–Pliocene boundary (approximately 5 Mya) similar to the divergences in many vertebrate taxa. The population‐level divergences within species occurred during the Pleistocene (0.1–1.8 Mya). The present study shows that similar patterns of diversification exist in vertebrate and invertebrate taxa. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 101 , 360–375.     

Checklist of Commelinaceae of Equatorial Guinea (Annobón,Bioko and Río Muni)

A checklist of Commelinaceae of Equatorial Guinea, comprising 46 taxa in 12 genera, is presented. The best represented genus is Palisota, with 11 species. Bibliographical references for Commelinaceae from Equatorial Guinea have been gathered and checked. Eleven species of Commelinaceae are recorded for the first time in the country. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 159 , 106–122.     

Identification of cryptic species of Miniopterus bats (Chiroptera: Miniopteridae) from Madagascar and the Comoros using bioacoustics overlaid on molecular genetic and morphological characters

The number of Miniopterus bat species on Madagascar and the nearby Comoros islands (Malagasy region) has risen from four to 11. These recently described cryptic taxa have been differentiated primarily based on molecular markers and associated a posteriori morphological characters that corroborate the different clades. Members of this Old World genus are notably conservative in morphology across their range. Several sites on Madagascar hold up to four small‐bodied taxa of this genus that are morphologically similar to one another, although they can be distinguished based on the tragus, an ear structure associated with echolocation. Miniopterus often emit species‐specific calls. In the present study, we analyze the bioacoustics of the 11 species of Miniopterus currently recognized from the Malagasy region, with an initial identification of the 87 recorded and collected individuals based on molecular markers and certain morphological characters. In most cases, bioacoustic parameters differentiate species and have taxonomic utility. Miniopterus griveaudi populations, which occur on three islands (Madagascar, Anjouan, and Grande Comore), showed no significant differences in peak echolocation frequencies. After running a discriminant function analysis based on five bioacoustic parameters, some mismatched assignments of Malagasy species were found, which include allopatric sister‐taxa and sympatric, phylogenetically not closely‐related species of similar body size. Because the peak echolocation frequencies of two species (Miniopterus sororculus and Miniopterus aelleni) were independent of body size, they were acoustically distinguishable from cryptic sympatric congeners. The small variation around the allometric relationship between body size and peak echolocation frequency of Malagasy Miniopterus species suggests that intraspecific communication rather than competition or prey detection may be the driver for the acoustic divergence of these two species. Our well‐defined echolocation data allow detailed ecological work to commence aiming to test predictions about the relative roles of competition, prey availability, and social communication on the evolution of echolocation in Malagasy Miniopterus species. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 104 , 284–302.     

Genetic patterns and pollination in Ophrys iricolor and O. mesaritica (Orchidaceae): sympatric evolution by pollinator shift

Ophrys iricolor and O. mesaritica are a pair of morphologically similar, closely related sexually deceptive orchids from the eastern Mediterranean. Ophrys iricolor is known to be pollinated by Andrena morio males and the specific pollinator of Ophrys mesaritica is determined as Andrena nigroaenea. Amplified fragment length polymorphism revealed O. iricolor and O. mesaritica to be genetically intermixed on the whole, although populations of O. iricolor and O. mesaritica in geographical proximity are strongly differentiated, suggesting that specific pollinators locally differentiate these taxa. Based on the available biological data and the system of pollinator attraction operative in Ophrys, we hypothesize that O. mesaritica may have arisen from O. iricolor by pollinator shift and that this is more probable than scenarios invoking hybridization as a result of mispollination by rare, non‐specific flower visitors or specifically attracted insects. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 159 , 583–598.     

Phylogenetic analysis and differentiation of Veronica subgenus Stenocarpon in the Balkan Peninsula

The Balkan Peninsula is considered the most important refugium for species during the Pleistocene glaciations and today harbours c. 2000 endemic species, but we know surprisingly little about the evolution of taxa in this region. Veronica saturejoides, V. thessalica and V. erinoides are a group of closely related alpine taxa endemic to the Balkan Peninsula. Here, we analyse four DNA regions [the nuclear chalcone synthase intron (CHSi) and ribosomal internal transcribed spacer (ITS) region and the plastid rpoB‐trnC spacer and trnL‐trnL‐trnF region] and amplified fragment length polymorphism (AFLP) fingerprints to provide a phylogenetic hypothesis for the relationships among these taxa. Additionally, we analyse leaf morphological characters used to distinguish the three subspecies of V. saturejoides. The analyses support the distinction of the three subspecies based on previously intuitively suggested characters. Nuclear chalcone synthase intron data indicate that the southern taxa are genetically much more diverse than the more northern V. saturejoides subsp. saturejoides. Phylogenetic relationships inferred from this region and AFLP fingerprints support the monophyly of V. saturejoides. In contrast, plastid DNA regions suggest a closer relationship of V. saturejoides subsp. saturejoides to V. thessalica. The most likely scenario involves introgression into V. saturejoides subsp. saturejoides from V. thessalica. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 159 , 616–636.     

Selection of candidate coding DNA barcoding regions for use on land plants

An in silico screen of 41 of the 81 coding regions of the Nicotiana plastid genome generated a shortlist of 12 candidates as DNA barcoding loci for land plants. These loci were evaluated for amplification and sequence variation against a reference set of 98 land plant taxa. The deployment of multiple primers and a modified multiplexed tandem polymerase chain reaction yielded 85–94% amplification across taxa, and mean sequence differences between sister taxa of 6.1 from 156 bases of accD to 22 from 493 bases of matK. We conclude that loci should be combined for effective diagnosis, and recommend further investigation of the following six loci: matK, rpoB, rpoC1, ndhJ, ycf5 and accD. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 159 , 1–11.     

Phylogeny‐based species delimitations and the evolution of host associations in symbiotic zoanthids (Anthozoa,Zoanthidea) of the wider Caribbean region

Zoanthids are marine cnidarians with simple morphologies that challenge our ability to delineate species. Phylogenetic analyses of internal transcribed spacer (ITS) sequences are consistent with six morphologically described species from the wider Caribbean region, and reveal four additional species that were not previously recognized. Histological examinations of unidentified species reveal cryptic Isozoanthus and Edwardsiidae (Actiniaria) species. Observations of zoanthids in situ reveal geographic distributions that range from regional to trans‐Atlantic. ITS and 16S data are consistent with hypotheses of paraphyly in some higher taxa of zoanthids; however, the clades of zoanthids recovered in both analyses can largely be defined by their host associations, thereby supporting phylogenetic conservatism in zoanthid–host association evolution. The single clear example of a zoanthid switching hosts was accompanied by a compensatory loss of endosymbiosis, which maintained the match in photosynthetic symbioses between zoanthids and sponge hosts. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 156 , 223–238.     

Phenotypic evolution of an Atlantic Forest passerine (Xiphorhynchus fuscus): biogeographic and systematic implications

We studied the phenotypic variation of the Atlantic Forest passerine Xiphorhynchus fuscus (Aves: Dendrocolaptidae) with the broad aim of addressing whether the history and type of forest affected the evolution of endemic taxa. We also tested whether the different subspecies and genetic lineages of X. fuscus could be considered full species. We collected plumage and body size measurements and, in combination with genetic data, used multivariate tests to evaluate the working hypotheses. Our results, combined with previous biogeographic analyses, indicate that vicariant events have been important determinants in the evolution of phenotypic characters of X. fuscus, once genetic isolation was complete. Our analysis also suggests that forest heterogeneity and ecotones are important factors in the early evolution of Atlantic Forest taxa, perhaps via divergent selection. Forest instability during the Pleistocene was critical in the evolution of phenotypic traits. We confirm that the subspecies atlanticus should be considered a full species. Other lineages or populations are also phenotypically differentiated but we do not suggest considering them as full species. They share high levels of gene flow and are part of a continuous latitudinal cline of phenotypic variation. Our study suggests that not all the historic events in the Atlantic Forest that affected the evolution of genetic lineages also influenced the evolution of phenotypic characters in the same direction and intensity. Undoubtedly, natural selection played a major role in the evolution of Atlantic Forest organisms. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 113 , 1047–1066.     

A Systematic Review on Phytochemistry,Ethnobotany and Biological Activities of the Genus Bunium L.

The aim of this review article is to present, for the first time, an appraisal of the phytochemical, ethnobotanical and pharmacological data on Bunium species. The literature search was conducted using the Scopus, Google Scholar and PubMed databases. The genus Bunium has been found to produce both essential oil (EO), mainly comprising monoterpenes and sesquiterpenes, and non-volatile components mainly coumarins and flavonoids. There are several pharmacological activities associated with the Bunium species, especially antioxidant, antibacterial and antifungal properties. The chemotaxonomic appraisal of the phytochemical pattern of the genus is in sink with the current classification of the family. Moreover, this review confirms the significant ethnobotanical and pharmacological potential of different Bunium species.     

Unravelling the stylar polymorphism in Melochia (Malvaceae): reciprocity and ancillary characters

Heterostyly is a genetic polymorphism in which plant populations possess two (distyly) or three (tristyly) morphs with flowers differing reciprocally in stigma and anther height. Sex organ deployment has been described as being highly variable among and within species of several distylous taxa belonging to different taxonomic groups. However, the number of studies considering within‐species disparities is still limited. For a better overview of the existing amount of variation that can occur within and between heterostylous species, we sampled 46 populations of six Melochia spp., a style‐polymorphic genus in Cuba. We characterized the floral morphology in all populations and described a set of ancillary characters per species. All of these Melochia spp. are distylous, except for the monomorphic M. nodiflora. The S‐morph produces fewer, larger pollen than L‐morphs, and has verrucose ornamentation. The L‐morph produces reticulate pollen and has larger stigmatic papillae than the S‐morph. The monomorphic M. nodiflora shows ancillary characteristics that are similar to the L‐morph individuals in the related species. As expected, there are differences in ancillary characters among species and also dissimilarities in reciprocity among and within species of Melochia. Our results highlight the importance of considering intraspecific variation in the morphometric characterization of heterostylous taxa. © 2014 The Linnean Society of London, Botanical Journal of the Linnean Society, 2014, 176 , 147–158.     

Morphometric analysis and taxonomic revision of the Vriesea paraibica complex (Bromeliaceae)

The species related to Vriesea paraibica (Bromeliaceae, Tillandsioideae) have controversial taxonomic limits. For several decades, this group has been identified in herbarium collections as V. × morreniana, an artificial hybrid that does not grow in natural habitats. The aim of this study was to assess the morphological variation in the V. paraibica complex through morphometric analyses of natural populations. Two sets of analyses were performed: the first involved six natural populations (G1) and the second was carried out on taxa that emerged from the first analysis, but using material from herbarium collections (G2). Univariate ANOVA was used, as well as discriminant analysis of 16 morphometric variables in G1 and 18 in G2. The results of the analyses of the two groups were similar and led to the selection of diagnostic traits of four species. Lengths of the lower and median floral bracts were significant for the separation of red and yellow floral bracts. Vriesea paraibica and V. interrogatoria have red bracts; these two species are differentiated by the widths of the lower and median portions of the inflorescence and by scape length. These structures are larger in the former and smaller in the latter. Of the species with yellow floral bracts, V. eltoniana is distinguished by longer leaf blades and scapes and V. flava is characterized by its shorter sepal lengths. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 159 , 163–181.     

Cytosystematics of the Simulium tuberosum group (Diptera: Simuliidae) in Thailand

The polytene chromosomes of 3347 larvae of the Simulium tuberosum group in Asia were analysed, representing the largest ever cytogenetic study of black flies in the Oriental Region. Band‐by‐band comparisons, relative to the established standard chromosome map for the subgenus Simulium, revealed 17 cytogenetically distinct taxa in Thailand, plus an 18th in China. Six of these taxa correspond to morphologically described species (S. doipuiense, S. rufibasis, S. setsukoae, S. tani, S. yuphae and S. weji). Recognition of the 18 taxa is based largely on unique inversions, either fixed or sex linked, primarily in the long arm of chromosome III. The greatest cytological diversity was discovered in the S. tani lineage, with ten cytoforms. This marked chromosomal diversification within S. tani is based largely on two inversions that have assumed different roles over evolutionary time, variously functioning in different combinations as fixed inversions, sex‐linked inversions and autosomal polymorphisms. Shared unique chromosomal features, relative to the subgeneric standard chromosome map, allowed evolutionary relationships among the cytotaxa to be inferred. Fluctuations in climate during the Pleistocene might have promoted differentiation of the Southeast Asian S. tuberosum group in isolated refugia such as mountains. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 155 , 289–315.     

Disjunct,highly divergent genetic lineages within two rare Eremophila (Scrophulariaceae: Myoporeae) species in a biodiversity hotspot: implications for taxonomy and conservation

Effective conservation management should target appropriate conservation units, but evolutionarily and genetically divergent lineages within nominal taxa are often unrecognized. The south‐western Australian biodiversity hotspot may harbour many cryptic taxa, as it contains many plant species with naturally fragmented population distributions. Using microsatellite markers, we tested the hypothesis that disjunct population groups in the rare species Eremophila microtheca and E. rostrata (Scrophulariaceae: Myoporeae) are highly genetically divergent and represent separate evolutionarily significant units (ESUs). Chromosome counts indicated that all individuals assessed were diploid (2n = 36). Genetic differentiation among disjunct population groups was highly significant (P < 0.001) for both E. microtheca (F_ST = 0.301–0.383; D_est = 0.756–0.774) and E. rostrata (F_ST = 0.325–0.346; D_est = 0.628–0.660), and was similar to their differentiation from allied species. These results, including high incidences of private alleles, suggest historical divergence among cryptic taxa within E. microtheca and E. rostrata. Population groups in E. rostrata have recently been taxonomically recognized as two subspecies. Our study suggests that E. microtheca should also be reassessed as two taxa or considered as two ESUs, and the southern occurrence should be listed as Critically Endangered. We suggest a precautionary approach for flora in this and similar landscapes, whereby historically wide geographical disjunctions are assumed to indicate separate units for conservation. © 2014 State of Western Australia. Botanical Journal of the Linnean Society © 2014 The Linnean Society of London, 2015, 177 , 96–111.