Species Concept Research Articles

Predictors of taxonomic splitting and its role in primate conservation

AbstractSpecies are the main unit used to measure biodiversity, but different preferred operational criteria can lead to very different delineations. For instance, named primate species have more than doubled in number since 1982. Such increases have been partly attributed to a shift away from the “biological species concept” (BSC) in favor of less inclusive species criteria. Critics of recent changes in primate taxonomy have suggested taxonomic splitting may be biased toward certain clades and have unfavorable consequences for conservation. Here, we explore predictors of taxonomic splitting across primate taxa since the initial shift away from the BSC nearly 40 years ago. We do not find evidence that net diversification rate, the rate of lineage formation over evolutionary time, is significantly linked to splitting, contrary to expectations if new species concepts and taxonomic methods identify incipient species. We also do not find evidence that research effort in fields where work has been suggested to motivate splitting is associated with increases in species numbers among genera. To test the suggestion that splitting groups is likely to increase their perceived risk of extinction, we test whether genera that have undergone more splitting have also observed a greater increase in their proportion of threatened species since the initial shift away from older taxonomic methods. We find no cohesive signal of taxonomic splitting leading to higher threat probabilities across primate genera. Thus, our analysis suggests that the threat statuses of primate species are not being overwhelmingly driven by splitting. Regardless, we echo warnings that it is unwise for conservation to be reliant on taxonomic stability. Species (however defined) are not independent from one another, thus, monitoring and managing them as such may not meet the overarching goal of conserving biodiversity.

The impact of species complexes on tree abundance patterns in Amazonia.

The impact of species complexes on tree abundance patterns in Amazonia.

Can pikas hold the umbrella? Understanding the current and future umbrella potential of keystone species Pika (Ochotona spp.)

The umbrella species concept is a frequently used concept in conservation since the conservation of an umbrella species may benefit other species. Keystone species are often suggested as potential umbrella species, but the validity of this approach remains uncertain. Moreover, climate change can have a multidirectional effect on the distribution of species, in which the distribution of umbrella species can be affected differently than that of beneficiary species. The validity of applying the umbrella species concept in conservation may thus be jeopardised by climate change. This study assessed the potential of two keystone species, the plateau pika ( Ochotona curzoniae ) and the Daurian pika ( Ochotona dauurica ), to be umbrella species for 13 potentially beneficiary species under current and future environmental conditions. Of these 13 species, five currently only co-occur with the plateau pika, five only with the Daurian pika, and three with both pika species. Current and future distributions of the pika species and potentially beneficiary species were predicted using bioclimatic and land-use variables. Range overlaps, Pearson correlations, niche similarity tests and relative suitability tests were performed to assess the umbrella potential of both pika species. Our results show that at present, both pika species may be considered to be umbrella species, benefitting several co-occurring species. However, species that currently co-occur with both pika species will not benefit from conservation of either of the pikas in the future years under climate change scenarios. The plateau pika loses its potential to act as umbrella species for two of the four species which currently may benefit. We can conclude that keystone species like pikas can act as umbrella species for carefully selected potentially beneficiary species under current conditions. Due to climate change related shifts in species distributions, they may however lose their umbrella species status in the future, which should be considered when selecting species conservation strategies. • The umbrella potential of two keystone species was explored under multiple scenarios of climate change. • Predicted umbrella potential of one keystone species was stronger than the other. • Umbrella potential is not necessarily maintained under future scenarios of climate change • Choice of beneficiary species highly influences the umbrella potential of keystone species. • Integration of predicted distribution range shifts in action plans is essential.

Reactive species conversion into 1O2 promotes substantial inhibition of chlorinated byproduct formation during electrooxidation of phenols in Cl−-laden wastewater

The generation of chlorinated byproducts during the electrochemical oxidation (EO) of Cl−-laden wastewater is a significant concern. We aim to propose a concept of converting reactive species (e.g., reactive chlorines and HO• resulting from electrolysis) into 1O2 via the addition of H2O2, which substantially alleviates chlorinated organic formation. When phenol was used as a model organic compound, the results showed that the H2O2-involving EO system outperformed the H2O2-absent system in terms of higher rate constants (5.95 × 10−2 min−1vs. 2.97 × 10−2 min−1) and a much lower accumulation of total organic chlorinated products (1.42 mg L−1vs. 8.18 mg L−1) during a 60 min operation. The rate constants of disappearance of a variety of phenolic compounds were positively correlated with the Hammett constants (σ), suggesting that the reactive species preferred oxidizing phenols with electron-rich groups. After the identification of 1O2 that was abundant in the bulk solution with the use of electron paramagnetic resonance and computational kinetic simulation, the routes of 1O2 generation were revealed. Despite the consensus as to the contribution of reaction between H2O2 and ClO− to 1O2 formation, we conclude that the predominant pathway is through H2O2 reaction with electrogenerated HO• or chlorine radicals (Cl• and Cl2•−) to produce O2•−, followed by self-combination. Density functional theory calculations theoretically showed the difficulty in forming chlorinated byproducts for the 1O2-initiated phenol oxidation in the presence of Cl−, which, by contrast, easily occurred for the Cl•-or HO•-initiated phenol reaction. The experiments run with real coking wastewater containing high-concentration phenols further demonstrated the superiority of the H2O2-involving EO system. The findings imply that this unique method for treating Cl−-laden organic wastewater is expected to be widely adopted for generalizing EO technology for environmental applications.

Effects of addition of 2-fucosyllactose to infant formula on growth and specific pathways of utilization by Bifidobacterium in healthy term infants.

Oligosaccharides in human milk support health via intestinal microbiome. We studied effects of addition of 2-fucosyllactose (2′FL) to the infant formula on infant growth, occurrence of adverse events (AE), and infant microbiome, including expression of microbial genes that metabolize 2′FL. Our hypothesis was that while 2′FL would not affect growth, it would cause changes in microbiome metabolism. In a double-blinded randomized controlled study fashion, the infant formula ± 2′FL or human milk was fed to healthy term infants for 16 weeks. Fecal samples obtained at baseline and week 16 were analyzed for microbial populations, metagenomic species concept (MGS), and genetics of gut metabolic modules (GMMs). There were no effects of addition of 2′FL on growth or AEs. There were no significant differences by feeding group in MGS richness or Shannon diversity at baseline, but formula groups each had significantly greater richness (p < 0.05) and diversity (p < 0.05) after 16 weeks of feeding than the breastfed group. While two glycosyl hydrolase (GH) families (GH42 and GH112) were significantly increased, two other GH families (GH20 and GH2) were significantly decreased in the test formula group compared to the control formula group; although modest, addition of 2′FL resulted in changes in microbiome in the direction of breastfed infants, consistent with internal metabolism of HMOs by Bifidobacterium.

Phylogenies in yeast species descriptions: In defense of neighbor-joining.

The neighbor-joining (NJ) method of tree inference is examined, with special attention to its use in yeast species descriptions. How the often-vilified method works is often misunderstood. More importantly, given the right kind of data, its output is a phylogram that illustrates a hypothetical phylogeny that is just as credible as that obtained by any other method. And as with any other method, the result is greatly affected by sampling intensity, particularly the number of aligned positions used for analysis. I address various allegations, including the claim that the method is phenetic, and, therefore, not phylogenetic. I argue that NJ is the most suitable tree inference method to use in yeast species descriptions, primarily because it is best at visually preserving the extent of sequence divergence between close relatives, which continues to be the primary criterion for yeast species delineation. The relevance of bootstraps in the application of the phylogenetic species concept is discussed.

&lt;i&gt;Corrigendum to&lt;/i&gt;: Sequence capture data support the taxonomy of &lt;i&gt;Pogonolepis&lt;/i&gt; (Asteraceae: Gnaphalieae) and show unexpected genetic structure

Variation in breeding systems between species of the same taxonomic group complicates the consistent application of species concepts, and perhaps even the logically consistent circumscription of species. Several genera of arid-zone ephemerals in the Angianthus clade (Asteraceae: Gnaphalieae: Gnaphaliinae) contain both outcrossing and non-outcrossing species. The latter are recognised by producing an order of magnitude fewer pollen grains per anther and an often reduced number of corolla lobes, and they are frequently more widespread than are the former. In its current taxonomy, the genus &lt;i&gt;Pogonolepis&lt;/i&gt; comprises an otherwise morphologically indistinguishable pair of one outcrossing and one non-outcrossing species. I generated sequence capture data to test the genetic segregation of &lt;i&gt;P. stricta&lt;/i&gt; and &lt;i&gt;P. muelleriana&lt;/i&gt; and the utility of sequence capture data for species circumscription and diagnostics. Phylogenetic analysis showed the two species to form two specimen clades, supporting the current taxonomy. Contrary to expectations, non-outcrossing &lt;i&gt;P. muelleriana&lt;/i&gt; exhibited lower gene concordance, in line with values expected from recombination, as well as higher heterozygosity than its outcrossing sister species. More research on the breeding system and population structure of the two species may be required to explain these results.

Assessing Morphological Species and Interspecific Relationships in North American Grapeferns (Sceptridium; Ophioglossaceae) Using ISSR Markers

Abstract— Relationships among North American Sceptridium (sensu Škoda) species are often difficult to assess because of few stable distinguishing characters and high intraspecific variability. We used ISSR-PCR to examine relationships among four samples of Holubiella, 24 samples representing four diploid North American Sceptridium species, and a Russian Sceptridium sample. Nine ISSR primers yielded 147 polymorphic loci. We generated three neighbor-joining dendrograms using a Jaccard, Nei &amp; Li, or Dice coefficient. All three coefficients cluster based solely on the presence of bands and not the absence. ISSR data analyses across all three coefficients were consistent with published analyses of DNA sequence data in supporting Holubiella as sister to all Sceptridium species sampled. Sister group relationships among the four Sceptridium species were not consistent across all three neighbor-joining analyses, and bootstrap support was generally low. However, 26 of the 29 samples consistently clustered with other samples of similar morphology, and these clusters generally supported current species concepts. In taxa such as Sceptridium, with low DNA sequence variability among species, ISSR-PCR may provide an important tool for evaluating morphologically defined species, but additional data are necessary for establishing robust hypotheses of phylogenetic relationships.

Checklist of the Elateridae (Coleoptera) of Montana, USA, with Taxonomic Notes

One hundred and eighty-four species of Elateridae in 54 genera are recorded from the state of Montana, representing an increase of 92 species from the 93 species recorded from previously published literature. Distribution within Montana is reported by county and includes 1,724 individual county records. EstimateS® was used to determine inventory completeness and predict the probable number of species expected in the state, which uses a Chao1 estimator. The Chao1 estimator mean predicts another 13 species remain to be discovered in the state. Selected genera are also provided with taxonomic notes that often highlight areas of potential future research and to highlight taxonomic issues or difficulties. The list also includes recently described genera to help establish limits for these new groups. The species concepts of Aeolus livens (LeConte, 1853) and Aeolus mellillus (Say, 1834) are clarified. A new combination, Megapenthes subtilis (LeConte, 1884), new combination, is proposed here. Specimens previously identified as Ampedus subtilis (LeConte) sensu Brooks 1960 are here identified as Ampedus nigricans Germar, 1834.

The Spectral Species Concept in Living Color.

Biodiversity monitoring is an almost inconceivable challenge at the scale of the entire Earth. The current (and soon to be flown) generation of spaceborne and airborne optical sensors (i.e., imaging spectrometers) can collect detailed information at unprecedented spatial, temporal, and spectral resolutions. These new data streams are preceded by a revolution in modeling and analytics that can utilize the richness of these datasets to measure a wide range of plant traits, community composition, and ecosystem functions. At the heart of this framework for monitoring plant biodiversity is the idea of remotely identifying species by making use of the ‘spectral species’ concept. In theory, the spectral species concept can be defined as a species characterized by a unique spectral signature and thus remotely detectable within pixel units of a spectral image. In reality, depending on spatial resolution, pixels may contain several species which renders species‐specific assignment of spectral information more challenging. The aim of this paper is to review the spectral species concept and relate it to underlying ecological principles, while also discussing the complexities, challenges and opportunities to apply this concept given current and future scientific advances in remote sensing.

Reproductive isolation is a heuristic, not a measure: acommentary on Westram et al., 2022.

Reproductive isolation is the heuristic basis of the biological species concept, but what is it? Westram et al. (this issue) propose that it is a measurable quantity, "barrier strength," that prevents gene flow among populations. However, their attempt to make the concept of reproductive isolation more scientific is unlikely to satisfy the diverse opinions of all evolutionary biologists. There are many different opinions about the nature of species, even under the biological species concept. Complete reproductive isolation, where gene flow is effectively zero, is regarded by some biologists as an important end point of speciation. Others, including Westram et al., argue for a more nuanced approach, and they also suggest that reproductive isolation may differ in different parts of the genome due to variation in genetic linkage to divergently selected loci. In contrast to both these approaches, we favour as a key criterion of speciation the stable coexistence of divergent populations in sympatry. Obviously, such populations must be reproductively isolated in some sense, but neither the fraction of the genome that is exchanged, nor measures of overall barrier strength acting on neutral variation will yield very precise predictions as to species status. Although an overall measure of reproductive isolation is virtually unattainable for these reasons, its early generation components, such as assortative mating, divergent selection, or hybrid inviability and sterility are readily measurable and remain informative. For example, we can make the prediction that to remain divergent in sympatry, almost all sexual species will require strong assortative mating, as well as some sort of ecological or intrinsic selection against hybrids and introgressed variants.

Linking Fennoscandian Species of Two Fungal Genera: A test case for linked open data

In Norway, Sweden and Finland, we all have our own taxonomy initiatives, mapping our biodiversity (Lahti and Skarp 2019, Sjödin Skarp 2019, Skarp et al. 2019). Together these countries make up most of Fennoscandia, sharing a large part of the fauna, flora and fungi. It was only natural for us to start cooperating through a Nordic Taxonomy Initiative, sharing expertise and knowledge. Our implementation of Linked Open Data (LOD) is a first step toward automated sharing of information about Fennoscandian species. By linking taxon concepts, we can share observations and facilitate our efforts to combat invasive alien species, as well as assessing conservation status of our native species (Liljeblad and Lahti 2019a, Liljeblad and Lahti 2019b). We picked the fungal genera Hygrophorus Fr. and Tricholoma (Fr.) Staude (Basiciomycetes: Agaricales) as test cases for matching species concepts between our countries. We downloaded lists of species from Checklistbank as a starting point, including synonym names and documenting the specific versions. However, the identifiers for these taxa are not independent of name and concept changes here, so this backbone was imported into taxonid.org. A spreadsheet with these taxa was then complemented with taxa from the three respective countries’ taxonomic databases. In Hygrophorus, there were 35 species with 28 present in Finland, 33 in Norway and 34 in Sweden. The mycologists among us discussed the full list during a virtual workshop and agreed upon how to interpret their respective taxonomies compared to the list at taxonid.org. Next, we copied the identifier for each species in taxonid.org to our respective national databases. Matching up all species of Hygrophorus took about 3 hours for 3 people, making for a total of 9 hours of effort excluding things such as exporting and preparing checklists for comparison. Adding the identifiers from taxonid.org into the respective national databases was a simple import of a maximum one hour each. We then did the same for the more species-rich genus Tricholoma. In the process, besides the links, we have established closer personal contact, synced our views on the taxonomy and had a chance to tidy up the nomenclature. When attempting to share more than taxonomic information, we have come to realize how our countries differ in usage of standard terms documenting residency, reproductive status as well as that of establishment means. For now, we will have to make do with a simple absence/presence, but having the actual taxon links is the prerequisite we are now starting to fulfill.

The Importance of Contact Zones for Distinguishing Interspecific from Intraspecific Geographic Variation.

With limited sampling, geographic variation within a single species can be difficult to distinguish from interspecific variation, confounding our ability to draw accurate species boundaries. We argue that thorough sampling and analysis of contact zones between putative taxa can determine if assortative mating or selection against hybrids exists (supporting the presence of two distinct species), or alternatively if mating is random among genotypes and admixture among adjacent populations is gradual and continuous (supporting geographic variation within a single species). Here, we test two alternative hypotheses for two pairs of named taxa at contact zones within the American milksnake (Lampropeltis triangulum) complex. A prior morphological analysis found areas of gradual intergradation among named taxa, and concluded that the taxa represented geographical races of a single polytypic species. In contrast, a subsequent analysis of gene sequence data, but with limited sampling near the contact zones, hypothesized distinct boundaries between species at the contact zones. At the contact zone between proposed species L. triangulum and Lampropeltis gentilis, we examined a $\sim$700 km-wide transect across the states of Kansas and Missouri, with thorough sampling and reduced-representation genomic-level sequencing, to test the two opposing taxonomic hypotheses. Our transect analyses included examinations of population structure, fixed differences, cline-fitting, and an admixture index analysis. These analyses all supported a gradual and continuous geographic cline across a broad intergrade zone between two geographic forms of L. triangulum, thus providing strong support for a single species in this region (and no support for the recognition of L. gentilis as a distinct species). At a second contact zone between proposed species L. triangulum and Lampropeltis elapsoides (but variously treated as species or subspecies by different researchers) in Kentucky and Tennessee, we re-evaluated morphological data. In this case, the contact zone analysis indicated sympatry and reproductive isolation of the two taxa, and thus strongly supported L. triangulum and L. elapsoides as distinct species. We conclude that detailed studies of contact zones, based on either genetic or morphological data, are essential for distinguishing intraspecific from interspecific variation in the case of widely and continuously distributed taxa. [Contact zones; speciation; species concepts; species delimitation; taxonomy.].

Rebuilding the foundation of late Paleozoic pinnid bivalve study (family Pinnidae)

AbstractThe early geologic history of family Pinnidae, a diverse and abundant component of mud-dominated shallow marine environments of the late Paleozoic, is obscured by ill-defined genus and species concepts. Mistakes in descriptions and reconstructions have provided a basis for suggestions that older taxa in the family differ from younger taxa and may not belong in family Pinnidae. This report provides improved documentation that removes the basis for the concept of divergence. Late Paleozoic genera and species have definite pinnid bivalve characters, including a dorsomarginal fold that holds the ligament, a thick outer columnar prismatic shell layer, and an equivalved, triangular shell, all of which provide evidence for confident assignment of the genus to family Pinnidae. The suggested synonymy of Aviculopinna with Pteronites is invalid, and genus Aviculopinna is limited to occurrence in Permian strata. The two genera belong in different families. A neotype is designated for genus Aviculopinna type species Aviculopinna pinnaeformis Geinitz from Gera, Germany, and a lectotype for Aviculopinna neukirchensis Langenhan from Nowy Kościół, Poland. Inferences on the life habits of Aviculopinna based on its occurrence in Poland are presented. An evaluation of the subterminal beak versus terminal beak concept in pinnids is presented and conclusion presented that there are few data available to support the concept or to test it. In its present form, the concept has no utility in the study of pinnid bivalves.

A monograph of the genus Polylepis (Rosaceae).

We present a monograph of the high Andean tree genus Polylepis (Rosaceae), based on a species concept considering morphological, climatic and biogeographic distinctness as indicators of evolutionary independence. In total, we recognize 45 species of Polylepis, grouped in five sections. Polylepissect.Sericeae is represented by 15 species in four subsections, P.sect.Reticulatae by seven species, P.sect.Subsericantes by three species, P.sect.Australes by two species and P.sect.Incanaee by three subsections with 18 species. We describe seven new species, one from Colombia (P.frontinensis), one from Ecuador (P.simpsoniae) and five from Peru (P.acomayensis, P.fjeldsaoi, P.occidentalis, P.pilosissima and P.sacra). Three species from Peru (P.albicans, P.pallidistigma and P.serrata) are re-instated as valid species. Two taxa from Bolivia (P.incanoides and P.nana) are elevated from subspecies to species rank. The morphology, habitat, distribution, ecology and conservation status of each species are documented. We also provide an identification key to the species of the genus and general introductions on taxonomic history, morphology, evolution, ecology and conservation.

Species richness, relative abundance and occupancy of ground-dwelling mammals denote the ineffectiveness of chimpanzee as flagship species

In conservation biology, flagship species are defined as species that can raise support for biodiversity conservation in a given place or social context. In the newly established Gishwati–Mukura National Park in Rwanda, the Eastern chimpanzee was considered such an ambassador. To test whether the flagship species concept was effective in the park, we studied species richness, relative abundance, and species distribution (occupancy) of medium- to large-sized, ground-dwelling mammals using camera trapping technology. The impact of three environmental and three anthropogenic variables on species distribution was investigated and the ecological diversity of the fauna in the national park assessed. Over a period of 9 months, two 4 × 4 camera trapping grids were deployed in Gishwati and Mukura Forest. Sampling effort in each forest equated to 32 and 29 camera trapping locations, yielding 258 and 242 independent photographic events of eight and six species, respectively. In both forests, the Emin's giant poached rat was the most frequently encountered species, while all other species showed high relative abundance only in Gishwati Forest. The relative abundance of the endangered Eastern chimpanzee in Gishwati Forest was 0.54, the estimated occupancy was 0.31. Single-species, single-season occupancy models revealed that forest cover, altitude and distance to forest edge influenced the detectability of L'Hoest's monkey and squirrel species, while no effect was found on their occupancy. Notably, no larger herbivore or carnivore species were observed in the park, while the flagship species, i.e., the Eastern chimpanzee, was relatively abundant. Moreover, in both forests, all detected carnivores were small- to medium-sized, suggesting a meso-predator release phenomenon, i.e., populations of medium-sized predators increased after the removal of larger, top carnivores, due to relaxed competition. It appears that the prioritization of the flagship species resulted in the neglect of other mammalian species, leading eventually into the demise of entire functional guilds. Based on these results, the Gishwati–Mukura NP was categorized as a ‘depleted forest’. We, therefore, strongly object chimpanzees as a suitable flagship species—at least in the Gishwati–Mukura NP—and recommend collating more knowledge on the release of meso-predators and the loss of forest ungulates to improve their future conservation in Afro-montane forest habitats.

Taxonomic uncertainty and the challenge of estimating global species richness

Taxonomic uncertainty and the challenge of estimating global species richness

On Living Beings: Biological and Philosophical Aspects

This is an interdisciplinary work (biology-philosophy) product of reflection on the challenges today presented by a biological vision of the world regarding questions, concepts and notions of cosmology (Philosophy of Nature). Based on and in dialogue with the current state of biological research, this work deals with certain cosmological problems such as that between the living and the inert, the traditional division between the soul or the vital vegetative principle, sensitive or intellective; the problem of individuation and the concept of species, among others; the solution found within classical philosophy in this paper takes into account the latest discoveries findings of modern biology.

The Warps and Wefts of a Polyploidy Complex: Integrative Species Delimitation of the Diploid Leucanthemum (Compositae, Anthemideae) Representatives.

Species delimitation—owing to the paramount role of the species rank in evolutionary, ecological, and nature conservation studies—is an essential contribution of taxonomy to biodiversity research. In an ‘integrative taxonomy’ approach to species delimitation on the diploid level, we searched for evolutionary significant units (the warps and wefts) that gave rise to the polyploid complex of European ox-eye daisies (Leucanthemum; Compositae-Anthemideae). Species discovery and validation methods based on genetic, ecological, geographical, and morphometric datasets were applied to test the currently accepted diploid morpho-species, i.e., morphologically delimited species, in Leucanthemum. Novel approaches were taken in the analyses of RADseq data (consensus clustering), morphometrics of reconstructed leaf silhouettes from digitized herbarium specimens, and quantification of species-distribution overlaps. We show that 17 of the 20 Leucanthemum morpho-species are supported by genetic evidence. The taxonomic rank of the remaining three morpho-species was resolved by combining genealogic, ecologic, geographic, and morphologic data in the framework of von Wettstein’s morpho-geographical species concept. We herewith provide a methodological pipeline for the species delimitation in an ‘integrative taxonomy’ fashion using sources of evidence from genealogical, morphological, ecological, and geographical data in the philosophy of De Queiroz’s “Unified Species Concept”.

Revised Species Delimitation in the Giant Water Lily Genus Victoria (Nymphaeaceae) Confirms a New Species and Has Implications for Its Conservation.

Reliably documenting plant diversity is necessary to protect and sustainably benefit from it. At the heart of this documentation lie species concepts and the practical methods used to delimit taxa. Here, we apply a total-evidence, iterative methodology to delimit and document species in the South American genus Victoria (Nymphaeaceae). The systematics of Victoria has thus far been poorly characterized due to difficulty in attributing species identities to biological collections. This research gap stems from an absence of type material and biological collections, also the confused diagnosis of V. cruziana. With the goal of improving systematic knowledge of the genus, we compiled information from historical records, horticulture and geography and assembled a morphological dataset using citizen science and specimens from herbaria and living collections. Finally, we generated genomic data from a subset of these specimens. Morphological and geographical observations suggest four putative species, three of which are supported by nuclear population genomic and plastid phylogenomic inferences. We propose these three confirmed entities as robust species, where two correspond to the currently recognized V. amazonica and V. cruziana, the third being new to science, which we describe, diagnose and name here as V. boliviana Magdalena and L. T. Sm. Importantly, we identify new morphological and molecular characters which serve to distinguish the species and underpin their delimitations. Our study demonstrates how combining different types of character data into a heuristic, total-evidence approach can enhance the reliability with which biological diversity of morphologically challenging groups can be identified, documented and further studied.