Article

Native New Zealand forget-me-nots (Myosotis, Boraginaceae) comprise a Pleistocene species radiation with very low genetic divergence

Authors:
To read the full-text of this research, you can request a copy directly from the authors.

Abstract

Reconstruction of molecular phylogenies is an important step towards understanding the evolutionary history of island plant radiations. The New Zealand forget-me-nots (Myosotis, Boraginaceae) comprise a lineage of over 40 closely related but morphologically and ecologically diverse species whose evolutionary history and taxonomy are unclear. Myosotis is a high priority for systematic research in New Zealand because a high proportion of these species are threatened, and many have restricted geographic ranges and occupy very specific habitats. Here, we investigated the relationships and age of Southern Hemisphere forget-me-nots by performing phylogenetic, molecular dating, and other analyses of DNA sequence datasets from representatives of nearly all described species. To this end, we used both chloroplast (atpI-atpH + rps16-trnQ) and nuclear ribosomal (ITS + ETS) DNA sequences, as well as amplified fragment length polymorphisms (AFLPs). Our analyses showed that genus Myosotis likely arose in the Northern Hemisphere during the Miocene with the ancestor of the Southern Hemisphere lineage arising in the Pleistocene and radiating shortly thereafter. The Southern Hemisphere Myosotis species have very low levels of genetic divergence and their relationships are largely unresolved, likely due to a combination of recent radiation, hybridization, and incomplete lineage sorting. Our results are compared to those of similar studies on other New Zealand species radiations, and implications for ongoing and future Myosotis taxonomic and evolutionary research are discussed.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the authors.

... It is currently estimated that there arẽ 80-100 species (Mabberley 2008;Weigend et al. 2016), but taxonomic revisions, particularly in the two centres of diversity, New Zealand and the Mediterranean region, are long overdue. The genus is regarded by conservation managers in New Zealand to be a high priority for taxonomic revision, where many of the~40 native species are considered to be Threatened or At Risk Meudt et al. 2015), using the New Zealand Threat Classification System (NZTCS; Townsend et al. 2008). Nearly all are endemic to New Zealand, with generally small, habitat-specific geographic ranges, and the last taxonomic treatment was completed over 50 years ago ). ...
... data), and, in the meantime, to systematically investigate all species of this large genus, an informal grouping system is being used (modified from Robertson 1989), in which southern hemisphere Myosotis can be separated into two main groups. Namely, ebracteate-erect (plants with ascending to erect scapes that do not have cauline leaves within the flowering portion of the inflorescence) and bracteate-prostrate (low-growing plants with prostrate to ascending scapes that have a flower in or near the axil of each cauline leaf of the inflorescence; see table in Meudt et al. 2015 for a completed list of all southern hemisphere species and informal species groups). Within each of these two main groups are further subgroups or species complexes. ...
... Since Moore's treatments, several studies have been published and theses written on New Zealand Myosotis breeding systems and pollination (Robertson 1989(Robertson , 1992; Lloyd 1991, 1993;Robertson and MacNair 1995;Brandon 2001), demography (Stanley et al. 1998;Dickinson et al. 2007), chromosome counts (Beuzenberg and Hair 1983;de Lange and Murray 2002) and phylogeny (Winkworth et al. 2002;Meudt et al. 2015). However, only recently has research begun to focus on taxonomy, including several new combinations (de Lange et al. 2010), description of two new South Island species (Lehnebach 2012b), clarification of some type issues (Lehnebach 2012a), revision of the M. petiolata Hook.f. ...
Article
A taxonomic revision of southern hemisphere bracteate-prostrate forget-me-nots (Myosotis L., Boraginaceae) is presented here. The group comprises mostly species endemic to New Zealand plus the South American Myosotis antarctica Hook.f. (also Campbell Island) and M. albiflora Hook.f. The statistical analyses of morphological data from herbarium specimens reported here support recognition of five main subgroups on the basis of habit. Excluding the M. pygmaea Colenso species group (M. antarctica, M. brevis de Lange & Barkla, M. drucei (L.B.Moore) de Lange & Barkla, M. glauca (G.Simpson & J.S.Thomson) de Lange & Barkla, and M. pygmaea), which is being treated elsewhere, 14 species are recognised in the following four remaining subgroups: (1) creeping-species group: M. matthewsii L.B.Moore, M. chaffeyorum Lehnebach, M. spatulata G.Forst., M. tenericaulis Petrie, and M. albiflora; (2) cushion-species group: M. uniflora Hook.f., M. pulvinaris Hook.f., and M. glabrescens L.B.Moore; (3) M. cheesemanii + M. colensoi species group: M. cheesemanii Petrie and M. colensoi J.F.Macbr.; and (4) M. lyallii species group: M. lyallii Hook.f. and new species M. retrorsa Meudt, Prebble & Hindmarsh-Walls. New species Myosotis umbrosa Meudt, Prebble & Thorsen and M. bryonoma Meudt, Prebble & Thorsen do not fit comfortably within these subgroups. Myosotis elderi L.B.Moore is treated as M. lyallii subsp. elderi (L.B.Moore) Meudt & Prebble. For each of the 14 species revised here, a key to species, descriptions, phenology, distributions, maps, illustrations, specimens examined and notes are provided. Some specimens examined do not fit within these species and require additional comparative studies, including with certain ebracteate-erect species, before taxonomic decisions can be made. Future research on these and other southern hemisphere Myosotis should incorporate the morphological data presented here, with additional genetic, cytological, pollen, and other data in an integrative systematic framework.
... Therefore, a new study on the taxonomic utility of pollen morphology in New Zealand Myosotis was undertaken. The emphasis was on the 'bracteate-prostrate' group (Robertson 1989;Meudt et al. 2015), as it is the current focus of forget-me-not taxonomic research (J. Prebble et al. 2015, unpubl. ...
... As the name suggests, plants in this group are largely prostrate rosette plants whose inflorescences have cauline leaves (sometimes called bracts) subtending the flowers, with habits ranging from very tightly compacted cushions with solitary flowers to creeping herbs with long, trailing branches with multiple flowers. By contrast, the remaining 33 described ebracteate-erect species and varieties comprise larger rosette plants whose inflorescences are erect and do not have cauline leaves subtending the flowers (see Meudt et al. 2015, Table 1). Notes: All specimens were originally collected from New Zealand except for those of M. albiflora from Chile; SI, South Island; NI, North Island; herbarium acronyms follow Index Herbariorum (Thiers, continuously updated). ...
... & Reut., M. congesta Shuttlew., M. discolor Pers. and M. persoonii Rouy, the latter of which is the sister species to the Southern Hemisphere lineage (Northern Hemisphere species sampling is incomplete; Winkworth et al. 2002;Meudt et al. 2015). The phylogeny of the Southern Hemisphere species is unresolved , and thus no insights can be gained from it regarding pollen evolutionary trends. ...
Article
The pollen of the informal bracteate-prostrate group of Southern Hemisphere Myosotis sect. Exarrhena (Boraginaceae: Cynogossoideae: Myosotideae) was investigated using scanning electron microscopy (SEM) to obtain taxonomically useful characters for delimiting species and species groups. Pollen grains of one to four individuals of each of 30 different taxonomic entities were imaged using SEM, scored for 16 different morphological characters, described and analysed. Pollen grains are small, heterocolpate, with 8?12 apertures, oblate spheroidal to prolate in equatorial view, with linear pseudocolpi which alternate with the colpori and can be partially to fully fused (?anastomosing?) to form an apocopial field (?polar cap?). Colpori ektoapertures are wider and often shorter than pseudocolpi, rhombic or narrowly rhombic with often circular or elliptical endoapertures. The exine is usually verrucate on the endoaperture membranes but densely and evenly granulate elsewhere. Statistical analyses of the pollen morphological dataset recovered three significant clusters, two of which contained the majority of individuals and coincided with the previously categorised Myosotis australis type pollen, while individuals in the third cluster had M. uniflora type pollen. Myosotis brevis (M. discolor type) and M. glabrescens (M. angustata type) represented two additional pollen types and thus had the most distinctive pollen of the whole dataset, whereas M. albiflora and M. tenericaulis showed high intraspecific variability. Important pollen characters separating the clusters included aperture number, polar cap presence, and P:E ratio (shape). Although most species could not be identified based solely on pollen morphology, species with similar habits clustered together, and pollen characters will be useful for delimiting species groups or species when combined with additional morphological, genetic or other datasets. Additional pollen studies of the remaining Myosotis species is warranted, including those from sect. Exarrhena with M. discolor type pollen and the ebracteate-erect species, as well as Northern Hemisphere sect. Myosotis.
... Plants of the other two-thirds of the species have an ebracteate-erect habit, i.e. ascending to erect inflorescences that do not have cauline leaves within the flowering portion of the inflorescence. In the informal grouping system currently being used for the southern hemisphere lineage (modified from Robertson 1989), the 'ebracteate-erect group' comprises approximately nine ill-defined and informal species groups, plus several species or tag-named taxa of unknown affinity (see Meudt et al. 2015;Meudt and Prebble 2018, for more details). For practical reasons, we have broken the ebracteate-erect group into four smaller studies of morphologically similar species. ...
... A subsequent study will address the taxonomy of the remaining~20 species and tag-named taxa in the final two species groups in the ebracteate-erect group, i. e. the M. angustata group, and the remainder of the lowland forest group (M. forsteri Lehm., M. venosa Colenso, and related tag names), plus those of 'uncertain affinities' (Robertson 1989;Meudt et al. 2015). ...
... The names of species and varieties as currently applied will be used throughout the manuscript through to the Discussion, and the new names are introduced in the 'Taxonomic treatment'. This study contributes to a larger research project that aims to revise the taxonomy of all New Zealand Myosotis species (Lehnebach 2012a(Lehnebach , 2012bMeudt et al. 2013Meudt et al. , 2015Meudt et al. , 2020Prebble et al. 2015Prebble et al. , 2018Prebble et al. , 2019Meudt 2016;Prebble 2016;Meudt and Prebble 2018). ...
Article
Macro-morphological data were analysed to assess the distinctiveness and revise the taxonomy of 14 species, varieties and tag-named taxa in five informal species groups of ebracteate-erect forget-me-nots endemic to New Zealand. The following nine species are recognised: Myosotis albosericea Hook.f., M. brockiei L.B.Moore & M.J.A.Simpson, M. capitata Hook.f., M. concinna Cheeseman, M. goyenii Petrie, M. laeta Cheeseman, M. monroi Cheeseman, M. rakiura L.B.Moore, and M. traversii Hook.f. Three species have two allopatric subspecies each in the South Island, distinguished by few, minor morphological characters, including Myosotis brockiei subsp. brockiei and M. brockiei subsp. dysis Courtney & Meudt subsp. nov., M. goyenii subsp. goyenii and M. goyenii subsp. infima Meudt & Heenan, and M. traversii subsp. cantabrica (L.B.Moore) Meudt comb. et stat. nov. and M. traversii subsp. traversii. Myosotis × cinerascens Petrie is hypothesised to be a rare natural hybrid involving M. traversii subsp. cantabrica and another species, possibly M. colensoi. Several vegetative and floral characteristics can distinguish the study taxa from one another and from other ebracteate-erect species. The nine species plus M. × cinerascens are included in the taxonomic treatment, and the key also includes other recently revised ebracteate-erect species.
... subgroup unknown 6, WELT SP089905 NZ: SI: Otago, Rock and Pillar Rage Originally described by Meudt and Prebble (2018), there is some uncertainty whether this species truly belongs in the bracteate-prostrate group, and to which subgroup it belongs, because, although most characters place it in the bracteate-prostrate group, it also shares some characters with the ebracteate-erect M. This study contributes to a larger research project that aims to revise the taxonomy of all New Zealand Myosotis species (Lehnebach 2012a(Lehnebach , 2012bMeudt et al. 2013Meudt et al. , 2015Prebble et al. 2015Prebble et al. , 2018Prebble et al. , 2019Meudt 2016;Prebble 2016;Meudt and Prebble 2018). ...
... The present revision is based almost entirely on analyses of morphological data from herbarium specimens and pollen morphology. Other data should be included in future studies to test these results, including morphological characters that may be taxonomically useful such as habit, colour and flower presentation (not included here because of lack of fresh or cultivated material; see Materials and methods), chromosome numbers and phylogenetic data (currently lacking for most species; see Meudt et al. 2015), and geographic distributions and ecological niches (not analysed in detail here). ...
... We hypothesise that M. australis subsp. australis and M. exarrhena represent two separate introductions into Australia (assuming a New Zealand origin for the southern hemisphere lineage; Meudt et al. 2015). Future morphological and genetic studies including many more ebracteate-erect species will determine the affinities and relationships of M. exarrhena. ...
Article
The three main aims of this study were to circumscribe the Myosotis australis R.Br. group, determine the taxonomic utility of pollen characters, and delimit species and revise their taxonomy using macro-morphological and palynological data. The M. australis group is here recircumscribed to comprise two species, M. saxatilis Petrie (Marlborough and Otago, New Zealand) and M. australis. Myosotis australis is a widespread, morphologically variable species with two subspecies. M. australis subsp. australis comprises all Australian and most New Zealand specimens, including M. mooreana Lehnebach, M. lytteltonensis (Laing & A.Wall) de Lange, and several white- or yellow-flowered tag-named taxa from New Zealand, whereas M. australis subsp. saruwagedica (Schltr. ex Brand) Meudt, Thorsen & Prebble, comb. et stat. nov. is endemic to New Guinea. The M. australis group can be distinguished from all other ebracteate-erect Myosotis plants sampled to date, including the Australian endemic, M. exarrhena F.Muell., by a suite of characters, i.e. included anthers, calyx with both retrorse and hooked trichomes, rosette leaf trichomes retrorse abaxially and oblique to the midrib adaxially, and leaf length : width ratio of >2 : 1. Other characters can distinguish the group from M. discolor Pers., M. arvensis (L.) Hill, and M. umbrosa Meudt, Prebble & Thorsen respectively. Pollen characters were not useful for species delimitation within the M. australis group, but they can help distinguish several species outside it, including natural hybrids of M. australis and M. exarrhena in Australia. Myosotis australis, M. saxatilis and M. exarrhena are included in the taxonomic treatment, whereas introduced species M. discolor and M. arvensis are included in the key only.
... Although not yet rigorously tested, recent results do suggest that modest increases in data set size are unlikely to overcome the problem of limited phylogenetic resolution. For example, Meudt, Prebble & Lehnebach (2015) used more than twice the number of sequence data of Winkworth et al. (2002), but resolution and support for relationships within the predominantly New Zealand clade of Myosotis L. were not substantially improved. ...
... Prebble, Meudt & Garnock-Jones, 2012) or between representatives of a species radiation (e.g. Meudt et al., 2015). One way to overcome this limitation might be to evaluate much larger numbers, on the order of tens or hundreds, of genetic loci. ...
... For other New Zealand plant groups, low resolution and support have often been assumed to reflect the comparatively short timeframe, often just a few million years, over which diversification occurred (e.g. Wagstaff et al., 2002Wagstaff et al., , 2006Chen et al., 2014;Meudt et al., 2015). In the case of L. scoparium, the suggestion of recent diversification is consistent with previous work (Thompson, 1989;Thornhill et al., 2012Thornhill et al., , 2015. ...
Article
Leptospermum scoparium (Myrtaceae) is a morphologically highly variable species found in mainland Australia, Tasmania and New Zealand. For example, in New Zealand up to six morphologically distinct varieties of this species have been described, although only two (var. scoparium and var. incanum) are now formally recognized. In the present study we provide a first examination of genetic diversity in this culturally and commercially important species with the aim of gaining insights into its origins and evolution. We used anchored hybrid enrichment to acquire sequence data from 485 orthologous low-copy nuclear loci for 27 New Zealand and three Australian accessions of L. scoparium and representatives of several other Leptospermum spp. The final concatenated data matrix contained 421 687 nucleotide positions of which 55 102 were potentially informative. Despite the relative large data set, our analyses suggest that a combination of low and incompatible data signal limits the resolution of relationships among New Zealand populations of L. scoparium. Nevertheless, our analyses are consistent with genetic diversity being geographically structured, with three groups of L. scoparium recovered. We discuss the evolutionary and taxonomic implications of our findings.
... There are two centers of diversity, Eurasia and New Zealand. New Zealand is the central point of a Southern Hemisphere species radiation; that is, species from Australia and South America are nested within the otherwise New Zealand clade (Winkworth et al. 2002;Meudt et al. 2015). Of the more than 40 species native to New Zealand, two-thirds are listed as threatened to some degree and at least nine taxonomically indeterminate entities have been identified, making a taxonomic revision of the genus a top priority for New Zealand species conservation . ...
... Based on morphology, informal species groups for the Southern Hemisphere representatives of the genus were proposed by Robertson (1989) and expanded upon by Meudt et al. (2015). Two major groupings are currently hypothesized: the "bracteate-prostrate" group (17 species, 16 native to New Zealand) and the "ebracteate-erect" group (29 species, 27 native to New Zealand) (see Table 1 in Meudt et al. 2015). ...
... Based on morphology, informal species groups for the Southern Hemisphere representatives of the genus were proposed by Robertson (1989) and expanded upon by Meudt et al. (2015). Two major groupings are currently hypothesized: the "bracteate-prostrate" group (17 species, 16 native to New Zealand) and the "ebracteate-erect" group (29 species, 27 native to New Zealand) (see Table 1 in Meudt et al. 2015). Meudt et al. (2015) attempted to delimit species groups phylogenetically within New Zealand Myosotis by using two plastid and two nuclear ribosomal markers but were hindered by a lack of resolution. ...
Article
Species delimitation in recent radiations is challenging because these species often display overlap in their expression of morphological characters. Here we analyze morphological characters measured from field-collected herbarium specimens and compare them to measurements from live plants grown in a common garden to determine reliable characters that could be used to delimit species in the Myosotis pygmaea (Boraginaceae) species group in New Zealand. This species complex is of primary interest because it includes many threatened species as well as several taxonomically indeterminate entities. The common garden experiment revealed high levels of morphological plasticity within the M. pygmaea species group, as plants in the common garden grew to be strikingly larger than those in the field. The M. pygmaea species complex was found to be a morphologically definable group, and several taxonomically indeterminate entities were placed as being either morphologically similar to the M. pygmaea species group or to other species complexes. In multidimensional scaling analyses of morphological data, of the five named species that make up the M. pygmaea species group, three formed separate clusters (M. pygmaea, M. glauca, and M. brevis), and the two others were indistinguishable from each other (M. antarctica and M. drucei). This study represents an important step towards a planned integrative taxonomic revision of the M. pygmaea species group, and highlights the value of morphological data collected from a common garden experiment.
... Forget-me-nots ( Myosotis L., Boraginaceae) are found in both the Northern and Southern Hemispheres, with a center of diversity in New Zealand. The M. pygmaea species group ( Meudt et al., 2015 ) Questions persist regarding the delimitation of these morphologically similar species ( de Lange et al., 2010 ), four of which appear on the New Zealand threatened species list ( de Lange et al., 2013 ). Indeed, of the 44 endemic New Zealand Myosotis taxa, 32 are considered threatened or at risk ( de Lange et al., 2013 ). ...
... A priority in the conservation management of members of this genus is to both accurately delimit species and understand the levels and structure of genetic diversity present. Low genetic diversity in New Zealand Myosotis , as evidenced by previous studies ( Meudt et al., 2013( Meudt et al., , 2015, suggests that additional molecular markers are needed. ...
Article
Full-text available
Premise of the study: Microsatellite loci were developed as polymorphic markers for the New Zealand endemic Myosotis pygmaea species group for use in species delimitation and population and conservation genetic studies. Methods and results: Illumina MiSeq sequencing was performed on genomic DNA from seedlings of Myosotis drucei. From trimmed paired-end sequences >400 bp, 484 microsatellite loci were identified. Twelve of 48 microsatellite loci tested were found to be polymorphic and consistently scoreable when screened on 53 individuals from four populations representing the geographic range of M. drucei. They also amplify in all other species in the M. pygmaea species group, i.e., M. antarctica, M. brevis, M. glauca and M. pygmaea, as well as 18 other Myosotis species. Conclusions: These 12 polymorphic microsatellite markers establish an important resource for research and conservation of the Myosotis pygmaea species group and potentially other Southern Hemisphere Myosotis.
... Lockhart et al. 2001, Winkworth et al. 2005, Lehnebach 2015. Some of these dispersal events have provided the ancestral stock for several plant radiations now found in sub-alpine and alpine areas of the country (Lockhart et al. 2001, Meudt et al. 2015. Mountain systems are of recent origin in NZ (4-2 Myr), and their formation created new habitats that facilitated diversification of several plant groups (Lockhart et al. 2001, Heenan & Mitchell 2003, Winkworth et al. 2005. ...
... Low genetic divergence in nuclear and plastid sequences has previously been reported in NZ plants, but mostly in species-rich alpine groups of recent origin (i.e. <10 Myr; Winkworth et al. 2005, Lehnebach 2015, Meudt et al. 2015. Although the NZ spider orchid is not an alpine group, it too seems to be of recent origin. ...
Article
Full-text available
Five new species of Corybas endemic to New Zealand, C. confusus, C. obscurus, C. sanctigeorgianus, C. vitreus, and C. wallii are described. These species are segregated from the Corybas trilobus aggregate based on morphometric and DNA fingerprinting (AFLP) analyses. A key to the new species is also provided, and their distribution and conservation status are included. Phylogenetic results showed that, despite the great morphological and ecological diversity of these orchids, genetic divergence between species is low, suggesting recent diversification. We also found evidence for multiple dispersal events from New Zealand to several offshore and sub-Antarctic islands.
... Pliocene (Figures 1, 2). Myosotis is an interesting group that also dispersed from Eurasia into the southern hemisphere, with a species radiation in New Zealand (40 species, Meudt et al., 2015). Although our sampling did not permit to infer the timing and direction of these events, the study of Meudt et al. (2015) showed that the diversification of Myosotis in New Zealand, Chile and New Guinea goes back to the Pleistocene, apparently from a northern hemisphere ancestor. ...
... Myosotis is an interesting group that also dispersed from Eurasia into the southern hemisphere, with a species radiation in New Zealand (40 species, Meudt et al., 2015). Although our sampling did not permit to infer the timing and direction of these events, the study of Meudt et al. (2015) showed that the diversification of Myosotis in New Zealand, Chile and New Guinea goes back to the Pleistocene, apparently from a northern hemisphere ancestor. Outside of the Cynoglossoideae older occurrences of LDD events are perhaps in the Moritziinae (Figure 1 and Table 1). ...
Article
Full-text available
Long-distance dispersal seems to be the main biogeographic event responsible for intriguing distribution patterns in plant groups in which sister taxa are separated by thousands of kilometers of distance across oceans and continents. The biotic and abiotic mechanisms behind such dispersal events are poorly understood and many attempts have been made to explain how plants can manage to disperse and survive these long journeys. The biogeographic history of Boraginaceae, a subcosmopolitan plant family with many disjunct clades, is here addressed and analyzed in the context of the different dispersal modes exhibited by the species. The lack of a clear pattern between the main dispersal events in Boraginaceae and the phylogenetic distribution of the dispersal modes indicates that no single dispersal mechanism can be associated with the events of dispersal in the family. Moreover, adaptations to different dispersal agents and unassisted dispersal modes in some clades might have promoted the diversification of Boraginaceae in various habitats across several continents. Our study reveals that long-distance dispersal is a very complex process that needs to be analyzed in the context of climatic and environmental changes and the response of plants and their dispersal vectors to these variable conditions.
... Many species, or their close relatives, also occur in cold, wet infertile areas at lower altitudes, suggesting colonization of the newly uplifted alpine areas by preexisting lineages (Heenan and McGlone, 2012), followed by allopatric speciation on mountain ranges isolated during Pleistocene interglacials (Winkworth et al., 2005). Molecular studies in speciose alpine genera (e.g., the Veronica complex (Hebe, Parahebe, Chionohebe, Hebejeebie), Myosotis, Ranunculus, Chionochloa) show rapid morphological diversification in the last 1--3 million years, but low genetic differentiation, leading to poor phylogenetic resolution for many genera, hybridizing or intergrading species complexes and a high prevalence of polyploids (Murray and Lange, 2011;Pirie et al., 2010;Lockhart et al., 2001;Winkworth et al., 2005;Wagstaff and Garnock-Jones, 1998;Meudt et al., 2015). Speciation in some groups is related to edaphic specialization; the endemic alpine rockcresses, Pachycladon (Brassicaceae), show a pattern of basal generalist species and radiation of specialists on particular rock types (Heenan and Mitchell, 2003). ...
... The New Zealand Threat Classification System (Townsend et al., 2008) determines the risk of extinction of species and changes in status over time, allowing for species to be prioritized for intervention. Many alpine species are highly range-restricted so feature on threatened species lists, for example 16 of the more than 40 Myosotis species in New Zealand are considered threatened due to very small ranges (Meudt et al., 2015). However, because the alpine environment is well represented in the conservation estate, management of alpine species is of less concern than lower altitude species threatened by habitat loss or introduced species. ...
... Pole 1994;McGlone et al. 2001), and also including many recent and rapid, mostly open-habitat, radiations (e.g. Wagstaff et al. 1999;Lockhart et al. 2001;Joly et al. 2009;Heenan and McGlone 2013;Meudt et al. 2015). ...
... Southern neo-endemism and the southern floristic gap Lower than expected species-level PD and PWE ( Fig. 2A, B) values reported here for South Island can possibly be explained by the presence of recently radiated species groups, because large areas of the South Island are identified by CANAPE as areas of neo-endemism (Fig. 2C). In support of this, it is well established that the South Island open-habitat and alpine flora includes many species-rich genera and recent radiations, including, for example, Asteraceae-Gnaphalieae (Smissen et al. 2004, Ford et al. 2007, Myosotis (Meudt et al. 2015), Pachycladon (Joly et al. 2009) and Ranunculus (Lockhart et al. 2001); see Heenan and McGlone (2013) for a recent account of the evolution of the New Zealand alpine flora. A prominent feature in the CANAPE analysis is an area including much of Westland and central South Island, where few cells are inferred to be areas of endemism. ...
Article
Categorical analysis of neo- and palaeo-endemism (CANAPE), phylogenetic diversity (PD) and phylogenetic weighted endemism (PWE) were used to explore patterns of diversity, endemism and biogeography in the indigenous vascular flora of the New Zealand archipelago. Distributional data comprising 213142 records for 436 genera and 2187 species and a phylogeny based mainly on rbcL sequences were used to calculate neo- and palaeo-endemism biodiversity metrics for 0.12° grid cells. Genus- and species-level analyses of PD revealed few significantly high-value cells mostly scattered in the northern North Island, and, for PWE, significantly high-value cells were concentrated in the northern North Island and northern offshore islands. CANAPE analyses suggested that palaeo-endemism is concentrated in northern North Island and the northern offshore islands, whereas neo-endemism is concentrated in South Island and the southern offshore islands. The areas of endemism highlighted by our analyses are compared with earlier biogeographic studies of endemism in the New Zealand flora. Some revision of previously suggested biogeographic boundaries is proposed, with the boundaries of the central South Island alpine gap being further north than previous studies have inferred, and the possibility that Pliocene marine transgression contributed to shaping the central North Island palaeo-endemism boundary is discussed.
... Molecular phylogenetic studies have effectively documented the monophyly of groups of island plants (Baldwin et al., 1998;Jones et al., 2014;Mort et al., 2015), confirming that the diversity seen in an island lineage has likely evolved in situ from a single colonization. Beyond this, inferring highly resolved relationships within insular clades with Sanger sequencing has proven quite challenging (e.g., Sang et al., 1994;Kim et al., 1996Kim et al., , 1999Kim et al., , 2007Francisco-Ortega et al., 1997;Gruenstaeudl et al., 2013;Meudt et al., 2015). The poor resolution is largely a result of the youth of the lineages. ...
Article
Oceanic islands have long been called natural laboratories for studying evolution because they are geologically young, isolated, dynamic areas with diverse habitats over small spatial scales. Volcanic substrates of different ages permit the study of different stages of divergence and speciation within plant lineages. In addition to divergence, the dynamic island setting is conducive to hybridization. Discussion will focus on the potential of systematic/ecological studies, in combination with genomic data from high throughput sequencing and an ever-increasing array of analytical techniques, for studying evolution in island plants. These studies may include: generation of highly resolved phylogenies to clarify the biogeography of speciation and whether divergence has occurred with or without gene flow; identification of the barriers to gene flow (extrinsic vs. intrinsic) of importance during divergence; documentation of historical and current hybridization events within island lineages; and elucidation of the genomic composition and ecology of hybrid populations in order to infer the evolutionary consequences of hybridization, such as the origin of stabilized homoploid hybrid species.
... The ranges of some 56 circum-North Temperate genera extend across the tropics into southern temperate regions, including Empetrum L., Euphrasia L. and Geum L. (Thorne 1972). Many of these genera have dispersed from north to south, including Euphrasia (Gussarova et al. 2008), Myosotis L. (Winkworth et al. 2005;Meudt et al. 2015) and Ranunculus L. (Emadzade & Hörandl 2011). In a review of plant distributions in North and South America, Raven (1963) reported 26 vascular plant species or species pairs having bipolar disjunctions, all but two of which had circumarctic or circumboreal distributions in the Northern Hemisphere. ...
Article
We present molecular data demonstrating that the New Zealand endemic Plagiochila caducifolia represents an isolated population of Plagiochila (sect. Arrectae) spinulosa, a species previously thought confined to the eastern Holarctic but which also occurs in Lesotho, southern Africa. In New Zealand, the wide distribution of P. spinulosa in undisturbed and relatively isolated habitats throughout the South Island is consistent with an indigenous, rather than adventive, species. Plagiochila spinulosa is the first reported bipolar disjunct species within the Plagiochilaceae. Although other bipolar disjunctions are known in vascular and non-vascular plants, they usually involve species with wider circumboreal or circumarctic distributions, presumably indicating an origin in the Northern Hemisphere. Most species of Plagiochila sect. Arrectae reproduce asexually by caducous leaves and have disjunct distributions; the significance of this correlation and biogeographic patterns in this lineage both require testing against additional data.
... Both clades were highly supported. The topology is highly congruent with earlier studies of Myosotis (Winkworth et al. 2002, Meudt et al. 2015. Our new species was embedded in the Eurasia clade (Fig. 1). ...
Article
Full-text available
Myosotis wumengensis, a distinct new species endemic to Yunnan Province, China, is described and illustrated. The new species differs from all Myosotis species in China by having exserted anthers and a long corolla tube. Phylogenetic analysis confirms the generic position of the new species. In addition, the pollen morphology of the new species is described.
... Potential advantages associated with the use of ITS are its conserved priming sites and ease of amplification, even with low DNA quantities, and ITS has been proposed as a DNA barcoding region for plants (Li et al. 2011). ITS has been utilized in numerous species-and population-level phylogenetic studies, and variation in the ITS region has successfully been used to reveal spatial genetic structure in plants (e.g., Collevatti et al. 2009;Beatty and Provan 2011;Volkova et al. 2013;Meudt et al. 2015). However, several disadvantages are associated with the use of ITS, including its occurrence in multiple arrays, the presence of orthologues, paralogues, and pseudogenes, high homoplasy, and poorly understood concerted evolution (Alvarez and Wendel 2003). ...
Article
Full-text available
A previous study of spatial genetic structure in brittlebush in the southwestern deserts based on chloroplast DNA variation revealed strongly differentiated populations and statistically significant associations between geography and genetic diversity, presumably associated with Pleistocene climatic oscillations. To expand this work and understand the spatial genetic structure of brittlebush populations more completely, we sought to compare the genetic diversity and structure of chloroplast DNA with that of nuclear ribosomal DNA (internal transcribed spacer) and a low-copy nuclear region developed for the Asteraceae (D22). Here we obtained 192 ITS and 206 D22 sequences from individuals sampled throughout the range and analyzed them with network, population genetic, demographic, hierarchical, spatial, and Bayesian analyses. Although there are differences in the signal present in each genetic region, several large-scale spatial patterns are congruent, including a split between the Sonoran and Mojave Deserts and differentiation of a taxonomic variety from the Cape Region of Baja California. In general, the distribution of genetic variation observed in D22 confirms and even refines patterns previously observed in the chloroplast region. In contrast, there is little to no geographic structure in the genetic variation of ITS, possibly due to the effects of multiple gene copies, reticulation, homoplasy, and concerted evolution. Hierarchical genetic structure differs sharply between nuclear regions and the chloroplast region, and this is likely due to differences not only in the evolution and inheritance of these regions, but also in the dispersal of pollen and seeds among brittlebush populations.
... In recent evolutionary radiations, genetic and morphological divergences are low because of the short evolutionary time scales involved [68][69][70] . According to Chao, et al. 60 , the main fauriei clade arose around 5 Myr, and most taxa diversified around 2 Myr. ...
Article
Full-text available
The Pteris fauriei group (Pteridaceae) has a wide distribution in Eastern Asia and includes 18 species with similar but varied morphology. We collected more than 300 specimens of the P. fauriei group and determined ploidy by flow cytometry and inferred phylogenies by molecular analyses of chloroplast and nuclear DNA markers. Our results reveal a complicated reticulate evolution, consisting of seven parental taxa and 58 hybrids. The large number of hybrid taxa have added significant morphological complexity to the group leading to difficult taxonomic issues. The hybrids generally had broader ranges and more populations than their parental taxa. Genetic combination of different pairs of parental species created divergent phenotypes of hybrids, exhibited by both morphological characteristics and ecological fidelities. Niche novelty could facilitate hybrid speciation. Apogamy is common in this group and potentially contributes to the sustainability of the whole group. We propose that frequent hybridizations among members of the P. fauriei group generate and maintain genetic diversity, via novel genetic combinations, niche differentiation, and apogamy.
... Lavor et al. 2018), incomplete lineage sorting and/or long generational times. Similar situations occur in other plant groups, such as Myosotis (Meudt et al. 2015), Astragalus (Bagheri et al. 2017), and Agave (Jiménez-Barron et al. 2020), which also show recent diversification, which complicates determination of the phylogenetic relationships between their species. ...
Article
Full-text available
Pilosocereus is one of the Cactaceae family’s most relevant genera in terms of the number of species and its wide geographical range in the Americas. Within Pilosocereus , five informal taxonomic groups have been recognized, one of which is P. leucocephalus group s.s. , whose phylogenetic relationships remain unresolved. Therefore, our objectives are to recognize the circumscriptions of the species in P. leucocephalus group s.s. and to corroborate the monophyly and phylogenetic relationships of this group through a set of morphological and molecular characters. This study is based on representative sampling along the broad distribution of this group in Mexico and Central America using multivariate and phylogenetic analyses. The morphological characters identified to contribute to species recognition and group formation are branch diameter, areole length, the areole length-width ratio, the distance between areoles, the length of the longest radial spine, and branch and spines colors. The chloroplast markers rpl16 , trnL-trnF , and petL-psbE and the nuclear marker AT1G18270 support the monophyly of the P. leucocephalus group s.s. , and two probable synapomorphies are suggested, including one transversion in rpl16 and another in petL-psbE . Together, our results demonstrate that sampled species of P. leucocephalus group s.s. encompass six species distributed in Mexico and Central America: P. alensis and P. purpusii in the western region, P. chrysacanthus and P. collinsii in the central region, and P. gaumeri and P. leucocephalus in the eastern region. A taxonomic key to recognized species is provided.
... The decision to cite genetic distance as a basis in deciding taxonomic rank needs to be taken in that context, as it is hardly unique; after all, there are other morphologically distinct New Zealand species exhibiting similar patterns of genetic variation, which are more closely allied to each other than they are to their Australian congeneric species. Consider New Zealand Lepidium (de Lange et al., 2013) and Myosotis (Meudt et al., 2014;Meudt, Prebble, 2018) as comparable examples. If genetic distance between Australian -New Zealand congeners was to be taken as a key deciding factor for their taxonomic ranks, then many widely accepted and morphologically discrete New Zealand allopatric species should perhaps also be reduced to subspecies because of their close relationship to each other and genetic distance from allied species in Australia or South America for that matter? ...
Article
Full-text available
A new combination, Trithuria brevistyla (K.A.Ford) de Lange & Mosyakin, is proposed for the recently described New Zealand, South Island endemic taxon originally published as T. inconspicua subsp. brevistyla K.A.Ford. Species rank for that taxon is advocated on the basis of morphological and reproductive distinctions between that species and the closely related North Island, New Zealand endemic T. inconspicua Cheeseman sensu stricto. Some general considerations on optional species versus subspecies ranks for plant taxa in need of conservation are provided.
... This includes, for example, a species that has been central to the debate on New Zealand biogeography Agathis australis, with a crown age of 16.11 Ma herein, and 23.0 Ma in Biffin et al. (2010). However, other crown dates derived herein are very similar to earlier studies, such as Hedycarya (16.18 Ma herein, and 17.24 Ma in Renner et al. 2010), Myosotis (2.16 Ma herein, and 1.97 Ma in Meudt et al. 2014), Liliaeopsis (6.25 Ma herein, and c. 6.6 Ma in Spalik et al. 2010), and Rhabdothamnus (25.12 Ma herein, and 22.0 Ma in Woo et al. 2011). Variation in dates across different studies can be caused by several factors, including the sampling of the closest relatives, DNA region sequenced and priors used. ...
Article
A colonisation history for 411 extant genera and 477 lineages of the vascular flora of New Zealand was constructed using the plastid rbcL gene. Molecular clock crown ages suggest that the Eocene-Oligocene transition extinction at 33.9 Ma was critical to the development of the extant flora as few lineages, mostly ferns and conifers, predate this event. Based on crown dates, almost all extant angiosperm lineages have established after the Eocene-Oligocene transition extinction. The Oligocene marine transgression had little discernible impact on the formation of the extant flora, as at the culmination of the inundation (22.0–25.0 Ma) fifty extant lineages of vascular plant were present and another eight lineages originated during this time. The majority of extant species (89%) originated after the end of the Miocene Thermal Optimum at about 15.0 Ma. Nearly 50% of the extant species have evolved during mountain uplift and glaciation of the late Pliocene-Pleistocene (0–4.99 Ma). Therefore, despite a residual contribution from the Eocene, Oligocene and early to mid Miocene periods, the New Zealand vascular flora essentially originated in the late Miocene and after.
... Sanger sequencing, microsatellite genotyping and AFLP of many New Zealand plant radiations resulted in phylogenetic trees and population genetic data exhibiting poor resolution, low support values, short branch lengths and evidence of interspecific gene flow (e.g. Heenan and Mitchell 2003;Smissen et al. 2004;Meudt et al. 2015;Heenan et al. 2021). Next-generation sequencing methods have been used to successfully determine the phylogenetic relationships of a number of rapid species radiations that had been unresolved with Sanger sequencing (e.g. ...
Article
Past studies of Sophora sect. Edwardsia using traditional phylogenetic and population genetic markers have been unable to produce a resolved species phylogeny of this recent radiation of shrubs and trees. Here we examined the relationships within and between the New Zealand species of Sophora sect. Edwardsia using next-generation sequencing. We generated genome-wide SNP data with double-digest restriction site-associated DNA sequencing (ddRADseq). Sophora prostrata was resolved as sister to the remaining species in all analyses. Relationships between the remaining taxa exhibited a high level of conflict with many of the genetic clusters reflecting geography rather than species boundaries. This result contrasts with a previous study, which was able to differentiate most species using genotype data from nine microsatellite loci. Overall our ddRADseq results indicate a high level of interspecific hybridisation and introgression within the group, which blurs the taxonomic boundaries throughout the distributional ranges of most species. Hybridisation and introgression among regional metapopulations comprising closely related species may increase the adaptive potential to respond to changing local conditions, and at the same time selection acts to maintain their genetic identity in the face of ongoing gene flow.
... Our divergence time estimates from the coalescent analyses ( Figure 3B) between Deschampsia cespitosa and the endemics point to a splitting off from a common ancestor in the late Miocene or Pliocene followed by subsequent cladogenesis in the lineage leading to the endemic taxa, the latest with the onset of the Pleistocene. The Pleistocene also marks the appearance of many other plant groups of open habitats, some species-rich [14,[22][23][24][25] and correlates with the formation of tall mountains and alpine conditions in the Southern Alps [21,31,83]. The resulting diverse alpine and montane habitats are also the likely trigger for speciation in the endemic Deschampsia lineage. ...
Article
Full-text available
The contrasting evolutionary histories of endemic versus related cosmopolitan species provide avenues to understand the spatial drivers and limitations of biodiversity. Here, we investigated the evolutionary history of three New Zealand endemic Deschampsia species, and how they are related to cosmopolitan D. cespitosa. We used RADseq to test species delimitations, infer a dated species tree, and investigate gene flow patterns between the New Zealand endemics and the D. cespitosa populations of New Zealand, Australia and Korea. Whole plastid DNA analysis was performed on a larger worldwide sampling. Morphometrics of selected characters were applied to New Zealand sampling. Our RADseq review of over 55 Mbp showed the endemics as genetically well-defined from each other. Their last common ancestor with D. cespitosa lived during the last ten MY. The New Zealand D. cespitosa appears in a clade with Australian and Korean samples. Whole plastid DNA analysis revealed the endemics as members of a southern hemisphere clade, excluding the extant D. cespitosa of New Zealand. Both data provided strong evidence for hybridization between D. cespitosa and D. chapmanii. Our findings provide evidence for at least two migration events of the genus Deschampsia to New Zealand and hybridization between D. cespitosa and endemic taxa.
... Alseuosmia A.Cunn., Epilobium L., Myosotis L. and Kunzea Rchb. (Lorimer, 2007;Meudt et al., 2014;de Lange, 2014;Shepherd et al., 2019;L.D. Shepherd, pers. comm.), species of which exhibit morphological disparity and are widely sympatric or even syntopic, often forming hybrid swarms in sites of prolonged human disturbance, but which maintain their distinctiveness in natural systems where they Table S2). ...
Article
We assessed the status of two New Zealand endemic morphodemes in the genus Sticta, currently treated as two separate taxa, Sticta filix and Sticta lacera. Both are green-algal lichens with a distinct stipe that grow in forested habitats and are suitable indicators of the indigenous vegetation health in forest ecosystems in New Zealand. They exhibit different morphologies and substrate ecologies: S. filix forms rather robust thalli, often on exposed trunks of phorophytes, with erect stems distinctly emerging from the substrate, whereas S. lacera is a more delicate lichen growing near the base of trees, usually among bryophyte mats or sheltered in the exposed portions of the phorophyte root-plate, with a prostrate, branched, stolon-like stem barely emerging from the substrate. Throughout their range, both taxa grow sympatrically and often in close proximity (syntopically). Despite the differences, ITS barcoding does not support the two morphodemes as separate species. In this study we assessed two possible explanations: (1) S. filix and S. lacera are discrete phenotypes of a single species, caused by developmental switching triggered by a discrete environmental variable, the propagules developing either on bare substrate or between bryophytes; and (2) the two morphodemes represent separate lineages, but ITS does not provide sufficient resolution to reflect this. We performed a quantitative analysis of morphological and ecological parameters, based on vouchered herbarium collections and field observations on iNaturalist NZ (https://inaturalist.nz), to assess the level of discreteness of the growth forms and to test for a correlation with the presence of a bryophyte mat. We further took advantage of an existing molecular data set from a target capture approach, comprised of 205 protein markers. This data set was used to establish a framework of percentage identities between pairs of the same and of different species among lobarioid Peltigeraceae and then to test whether the S. filix/lacera pairing fell closer to a within-species or a between-species pairing. The morphometric analysis of herbarium material resolved S. filix and S. lacera as two discrete morphs with little overlap, supported by numerous observations on iNaturalist NZ. However, whereas herbarium material suggested a significant association of the lacera morph with bryophyte mats, no such pattern was evident from field images on iNaturalist NZ, in which both morphs frequently associated with bryophyte mats. This highlights the limitations of herbarium material to correctly assess substrate ecology, whereas iNaturalist NZ postings had issues with correct identifications, given that especially S. lacera is easily confused with Pseudocyphellaria multifida. Based on the target capture data, the percentage identity of the S. filix/lacera pairing (99.43%) was significantly higher than that of all 12 between-species pairings (93.20-98.01%); it was at the same time lower than that of all within-species pairings (99.63-99.99%) but significantly so only in comparison with five out of the eight within-species pairings. The target capture approach is thus inconclusive, but the combination of all data suggests that S. filix and S. lacera are not discrete morphodemes of a single species but represent two separate lineages which emerged recently and hence cannot be resolved using the ITS barcoding marker or even a deeper phylogenomic approach based on protein-coding markers. We propose transplantation experiments and the application of RADseq to further assess this situation.
Article
Delimiting species boundaries in recent plant radiations can be challenging. The New Zealand native Myosotis pygmaea (Boraginaceae) species group is a case in point. This species complex is of interest as it includes threatened species as well as possibly threatened unnamed putative taxa. Integrative taxonomic approaches using multiple lines of evidence are frequently used to overcome the difficulties of identifying lineages resulting from recent radiations. Here we analyse genotypic data from nearly 500 Myosotis individuals using microsatellite markers, and compare and co‐analyse this dataset with previously published morphological data. Within the M. pygmaea group, several genetic clusters can be identified, none of which align exactly with the current taxonomy and morphological variation previously identified. When co‐analysing the molecular and morphological data, M. brevis can be distinguished from the remainder of the M. pygmaea species group, but no other species or previously recognised morphological groups are supported. Other groupings within the molecular dataset appear to reflect geographic structure. Within the M. pygmaea species group, the resulting pattern of low within, and high between, population genetic variation is consistent with self‐fertilization and low levels of seed dispersal.
Article
Evolutionary priority effects, where early-arriving lineages occupy niche space via diversification and preclude dominance of later arrivals, have been observed in alpine and forest communities. However, the potential for evolutionary priority effects to persist in an era of rapid global change remains unclear. Here, we use a natural experiment of historical disturbance in New Zealand to test whether anthropogenic changes in available habitat and nonnative invasion eliminate the role of evolutionary priority effects in community assembly. We also test whether evolutionary priority effects diminish with decreasing resource availability. Older plant clades, as estimated by clade crown age, were relatively more abundant in both primary and secondary grassland. Relative abundance in primary grassland decreased with clade stem age, but only weakly. However, for both clade age estimates, relative abundance decreased with age when nonnative biomass was high and soil moisture was low. Our data show that patterns in community structure consistent with evolutionary priority effects can occur in both primary and secondary grasslands, the latter created by anthropogenic disturbance. However, nonnative invasion may overwhelm the effect of immigration timing on community dominance, possibly as a result of high immigration rates and preadaptation to anthropogenically modified environments.
Article
Background There are conflicting views between palaeobotanists and plant systematists/evolutionary biologists regarding the occurrence of plant speciation in the Quaternary. Palaeobotanists advocate that Quaternary speciation was rare despite opposing molecular phylogenetic evidence, the extent of which appears underappreciated. Aims To document, describe and discuss evidence for Quaternary plant speciation across different geographical regions based on dated molecular phylogenies and related studies. Methods From a search of the literature we compiled a selection mainly of dated molecular phylogenies from all continents (except Antarctica) and from all major climate zones. Results Molecular phylogenetic analyses and related studies show that Quaternary plant speciation and radiations occurred frequently and that in many instances Quaternary climatic oscillations were likely important drivers of them. In all geographical regions studied Quaternary plant speciation and radiations were particularly evident in mountainous areas and arid regions, and were also prevalent on all major oceanic archipelagos. Conclusions Based on our survey of the molecular phylogenetic and related literature we propose there is now overwhelming evidence that plant speciation and radiations were ubiquitous during the Quaternary. We therefore reject the view of palaeobotanists that plant speciation was rare during this period and briefly discuss possible reasons for this discrepancy.
Article
Full-text available
Chloroplast DNA sequences are a primary source of data for plant molecular systematic studies. A few key papers have provided the molecular systematics community with universal primer pairs for noncoding regions that have dominated the field, namely trnL- ...
Article
Full-text available
Cryptantha (Boraginaceae) is a group of approximately 200 annual and perennial species, representing two-thirds of the diversity within subtribe Cryptanthinae. The genus exhibits an amphitropic distribution, occurring in temperate and desert regions of western North and South America. Fifty samples of 45 species of Cryptantha s. l., exemplars of the related genera Amsinckia, Pectocarya, and Plagiobothrys, and four outgroup taxa were sequenced for two gene regions, the nuclear ribosomal gene, ITS, and the trnLUAA intron region of the chloroplast genome. These data were used to assess phylogenetic relationships using parsimony, maximum likelihood, and Bayesian inference methods. Cryptantha s. l. was found to be polyphyletic, with its members placed among several well-supported clades. Based on these analyses, we propose resurrection of the genera Eremocarya, Greeneocharis, Johnstonella, and Oreocarya, and recognition of a newly delimited Cryptantha s. s. The related genera Amsinckia and Pectocarya were resolved as monophyletic and most closely related to various clades within Cryptantha s. l. Plagiobothrys was resolved as polyphyletic in three clades, these clades corresponding to previously named sections or groups of sections. The Cryptanthinae is supported as monophyletic. Character trait analyses support the multiple, derived evolution of perenniality, reduction in nutlet number, nutlet heteromorphism, smooth nutlet sculpturing, heterostyly, and cleistogamy. Although sampling is incomplete, this study generally supports the hypothesis of repeated, unidirectional dispersal events, from North to South America. Genera resurrected include: Eremocarya, Greeneocharis, Johnstonella, and Oreocarya. New combinations include.
Article
Full-text available
We present a new open source, extensible and flexible software platform for Bayesian evolutionary analysis called BEAST 2. This software platform is a re-design of the popular BEAST 1 platform to correct structural deficiencies that became evident as the BEAST 1 software evolved. Key among those deficiencies was the lack of post-deployment extensibility. BEAST 2 now has a fully developed package management system that allows third party developers to write additional functionality that can be directly installed to the BEAST 2 analysis platform via a package manager without requiring a new software release of the platform. This package architecture is showcased with a number of recently published new models encompassing birth-death-sampling tree priors, phylodynamics and model averaging for substitution models and site partitioning. A second major improvement is the ability to read/write the entire state of the MCMC chain to/from disk allowing it to be easily shared between multiple instances of the BEAST software. This facilitates checkpointing and better support for multi-processor and high-end computing extensions. Finally, the functionality in new packages can be easily added to the user interface (BEAUti 2) by a simple XML template-based mechanism because BEAST 2 has been re-designed to provide greater integration between the analysis engine and the user interface so that, for example BEAST and BEAUti use exactly the same XML file format.
Article
Full-text available
Adaptive radiations such as the Darwin finches in the Galapagos or the cichlid fishes from the Eastern African Great Lakes have been a constant source of inspiration for biologists and a stimulus for evolutionary thinking. A central concept behind adaptive radiation is that of evolution by niche shifts, or ecological speciation. Evidence for adaptive radiations generally requires a strong correlation between phenotypic traits and the environment. But adaptive traits are often cryptic, hence making this phenotype-environment approach difficult to implement. Here we propose a procedure for detecting adaptive radiation that focuses on species' ecological niche comparisons. It evaluates whether past ecological disparity in a group fits better a neutral Brownian motion model of ecological divergence or a niche shift model. We have evaluated this approach on New Zealand rockcresses (Pachycladon) that recently radiated in the New Zealand Alps. We show that the pattern of ecological divergence rejects the neutral model and is consistent with that of a niche shift model. Our approach to detect adaptive radiation has the advantage over alternative approaches that it focuses on ecological niches, a key concept behind adaptive radiation. It also provides a way to evaluate the importance of ecological speciation in adaptive radiations and will have general application in evolutionary studies. In the case of Pachycladon, the high estimated diversification rate, the distinctive ecological niches of species, and the evidence for ecological speciation suggest a remarkable example of adaptive radiation.
Article
Full-text available
A selection of Boraginaceae genera was used to obtain a framework for the phylogenetic position of some tribes belong to subfamily Boraginoideae and genera within tribe Eritrichieae (Heterocaryum, Rochelia, Eritrichium, Lappula, Lepechiniella, and Asperugo) and related species. Our results were produced on the basis of nrDNA ITS and cpDNAtrnL-F sequences. The combined nrDNA ITS trnL-F data confirm four main clades of Boraginoideae comprising Echiochileae, Boragineae, Lithospermeae, and Cynoglosseae s. l. (including Eritrichieae, Cynoglosseae s. str., and Myosotideae). The tribe Eritrichieae itself at the current status is paraphyletic; some members, for example Asperugo procumbens, Lepechiniella inconspicua, Myosotidium hortensia, and Cryptantha flavoculata are placed out of the core tribe Eritrichieae. The genus Heterocaryum is monophyletic and allied with a subclade of genera Lappula, Lepechiniella, Eritrichium, and Rochelia. Rochelia is monophyletic, but Eritrichium and Lappula are non-monophyletic. Lepechiniella is nested among a group of Lappula species.
Article
Full-text available
A reappraisal of the conservation status of the indigenous New Zealand vascular plant flora is presented. The list comprises 792 taxa (34% of New Zealand's total indigenous vascular flora) in the following categories: Extinct 4 taxa, Acutely Threatened 122 taxa (comprising 47 taxa Nationally Critical, 54 Nationally Endangered, 21 Nationally Vulnerable), Chronically Threatened 96 taxa (comprising Serious Decline 26 taxa, Gradual Decline 70 taxa), At Risk 499 taxa (comprising Sparse 126 taxa, Range Restricted 373 taxa), Non-resident Native 26 taxa (comprising Vagrant 16 taxa, Colonist 10 taxa), and Data Deficient 45 taxa. A further 208 plants are listed as Taxonomically Indeterminate, being those which might warrant further conservation attention once their taxonomic status is clarified. A further 31 named taxa and 18 rated as Taxonomically Indeterminate, and previously considered to be threatened and/or uncommon, are removed from this updated listing. A concordance of plant names is provided. The lists presented use a new threat classification system developed by the New Zealand Department of Conservation for sole use within this country. This paper represents the first time the entire known indigenous vascular flora has been assessed from a conservation perspective since the mid 1970s. A brief analysis of the patterns of rarity exhibited by the taxa listed is presented.
Book
Full-text available
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below was reassessed using the New Zealand Threat Classification System (NZTCS). A full list is presented, along with a statistical summary and brief notes on the most important changes. This 2012 list replaces all previous NZTCS lists for vascular plants.
Article
Full-text available
Large floral displays allow high fecundity but in addition have been postulated to disproportionately attract pollinator visitation, resulting in increased pollination rates to flowers on large plants. Balancing this advantage, however, is the presumed cost of increased self-pollination through transfer of pollen within plants (geitonogamy). Protohystricia huttoni (Tachinidae) responded to larger floral displays in Myosotis colensoi in its native habitat in New Zealand by making more plant-visits per hour, visiting more flowers at each visit, but visiting a declining proportion of the flowers available. As a result, flowers were visited at approximately the same rate (similar to 1 visit per flower per hour) on all display sizes. Pollen deposition, pollen receipt and seed set all varied independently of flower number confirming the even pollinator service to flowers across all plant sizes. Bombus terrestris and Apis mellifera both responded in a very similar way to variation in flower number in naturalised Mimulus guttatus in Britain and, similarly, the proportion of flowers successfully pollinated was independent of flower number. The data presented offer little support for the hypothesis of facilitation of visitation to individual flowers on large displays. Instead, pollinators appear to adopt an ''ideal free distribution'' and utilise floral resources evenly across all plant sizes.
Article
Full-text available
Documented chromosome numbers are reported for 33 species, 7 subspecies, 9 varieties, 2 forma, 2 hybrids, and 14 taxa of uncertain rank from 21 families ofangiosperms. Thirty‐eight of these are for previously uncounted taxa and hybrids. The majority of the counts are for nationally uncommon and threatened, or newly described plants. In the majority of genera the numbers follow established patterns but new examples of polyploid series have been found in New Zealand species of Crassula and Gratiola.
Article
Full-text available
Understanding the evolutionary history and biogeography of the New Zealand alpine flora has been impeded by the lack of an integrated model of geomorphology and climate events during the Late Miocene, Pliocene and Pleistocene. A new geobiological model is presented that integrates rock uplift age, rate of uplift and the resulting summit elevations in the Southern Alps (South Island) during the last 8.0 million years with a climate template using the natural gamma radiation pattern from the eastern South Island Ocean Drilling Program Site 1119 that covers the past 3.9 million years. This model specifically defines the average treeline in relation to mountain height, allowing predictions as to the timing of the formation of the alpine zone and other open habitats. This model predicts open habitats such as rock bluffs, tussock grasslands and riverbeds would have been available from about 4.0-3.0 Ma, coinciding with the initiation of summit uplift and a cooling climate providing an opportunity for the evolution of generalist alpine and open-habitat herbs and shrubs. Alpine habitats began to form at about 1.9 Ma and were a permanent feature of the Southern Alps from about 0.95 Ma. Specialist alpine plants confined to alpine habitats can have evolved only within this period once the alpine zone was persistent and widespread. Bog habitats are likely to date from the Late Miocene (c. 6.0 Ma), and the specialist bog species would have evolved from this time. Molecular-clock dates for DNA sequences from species of specialist alpine habitats, generalist open habitats, and bog habitats are consistent with predictions made on the basis of the model.
Article
Full-text available
Chromosome numbers are reported for 112 endemic or indigenous vascular plants from New Zealand. Ninety one of these are new and the remainder provide confirmation of previous counts. Many of the counts fill gaps in the available record of chromosome numbers of New Zealand plants and a summary table provides a list of the genera where numbers remain to be determined. With the publication of these numbers, c. 85% of the indigenous vascular flora of New Zealand now has a documented chromosome number.
Book
Full-text available
This is the second approximation of New Zealand’s indigenous vascular plant taxa sponsored by the New Zealand Plant Conservation Network. This list covers the New Zealand Botanical Region as defined by Allan (1961, Flora of New Zealand, Vol. I, Government Printer, Wellington). That means it covers those taxa indigenous to the Kermadec, Three Kings, North, South, Stewart, Chatham, Antipodes, Bounties, Snares, Auckland, Campbell, Macquarie islands of the New Zealand subcontinent. The indigenous flora of Lord Howe and Norfolk Island have been specifically excluded from this list because, although they are part of the New Zealand subcontinent, they were not included by Allan in his concept of the New Zealand Botanical Region.
Article
Full-text available
Phylogenetic analyses of nuclear DNA external transcribed spacer (ETS) and chloroplast DNA trnL–trnF markers were undertaken to reconstruct the evolutionary history of the South Pacific genus Melicytus. Bayesian analyses of the ETS sequence data produced a phylogenetic tree with several well supported groups, including clades comprising: (1) species from Australia, Tasmania and Lord Howe Island; (2) the Norfolk Island M. latifolius and New Zealand off-shore island M. novae-zelandiae subsp. novae-zelandiae; (3) the large-leaved M. ramiflorus complex; (4) M. fasciger and M. micranthus; and (5) M. obovatus and allies from the Cook Strait region. Phylogenetic analysis of trnL–trnF sequence data also retrieved some of these groups although, in general, was not as well resolved. The relationships of M. lanceolatus are equivocal, as in the ETS phylogeny it is sister to a clade comprising the large-leaved tree species M. fasciger and M. ramiflorus complex and the small-leaved M. micranthus, whereas in the trnL–trnF phylogeny it is sister to a clade of small-leaved shrub species such as M. alpinus and M. crassifolius. Several biogeographic patterns are evident, with dispersal to the west from New Zealand, to Australia, involving small-leaved shrub species. Dispersal to the north from New Zealand, to Norfolk Island and Fiji, involves large-leaved tree species. The sex expression is documented for all named species and undescribed entities, with these being either hermaphroditic or dioecious. When sex expression is mapped onto the phylogeny, the hermaphroditic system is inferred to have evolved from the dioecious system. New chromosome counts are presented for M. angustifolius (2n = 64) and M. dentatus (2n = 32), and earlier counts of 2n = 64 are confirmed for M. crassifolius and M. alpinus.An additional 17 counts are provided for two natural hybrids and several undescribed entities from Australia and New Zealand. The polyploid chromosome number of 2n = 64 occurs most frequently in small-leaved divaricate plants with hermaphroditic flowers. When chromosome numbers are plotted onto the phylogeny it is inferred that high polyploids (e.g. 2n = 64) and small-leaved shrubs have evolved from large-leaved trees with functional diploid (e.g. 2n = 32) chromosome numbers.
Article
Full-text available
indigenous New Zealand vascular plant flora is presented using the 2008 version of the threat classification system developed for the New Zealand Department of Conservation. The list comprises 897 taxa (38% of New Zealand’s total indigenous vascular flora) in the following categories: Extinct—6 taxa, Threatened—180 taxa (comprising 91 Nationally Critical taxa, 45 Nationally Endangered, and 44 Nationally Vulnerable), At Risk—651 taxa (comprising 83 Declining, 6 Recovering, 20 Relict, and 542 Naturally Uncommon taxa), 25 taxa listed as either Vagrant (12) or Coloniser (13), and 35 as Data Deficient. A further 171 plants are listed as taxonomically indeterminate, being those which might warrant further conservation attention once their taxonomic status is clarified. Forty-four recognised taxa and 26 plants rated as taxonomically indeterminate, and previously considered to be threatened and/or uncommon, are removed from this updated listing. A brief analysis of the patterns of rarity exhibited by the listed taxa is presented. Overall, the conservation status of the New Zealand indigenous vascular plant flora is worsening, with 7.6% of this flora now regarded as threatened with extinction. A concordance of plants names from the 2004 listing is provided.
Article
Full-text available
187 taxa (170 species, 9 subspecies, 8 varieties), 5 hybrids (four putative, one artificial), and 18 of uncertain rank from 50 families (84 genera; 2 lycophyte, 11 pterophyte and 71 anthophyte). Of these, 189 counts are new for the New Zealand flora (167 of these are from named taxa). Many of the counts reported are from more poorly investigated families (e.g., Cyperaceae, Lycopodiaceae, Potamogetonaceae) and genera (e.g., Desmoschoenus, Freycinetia, Lycopodiella, Lycopodium, Potamogeton, Schoenus) indigenous to New Zealand, or from nationally uncommon and/or threatened taxa (e.g., Eleocharis neozelandica, Hebe societatis, Myriophyllum robustum, and Pittosporum dallii) and/or newly described plants (e.g., Gingidia grisea, Olearia adenocarpa), while three counts are from naturalised species (Alternanthera sessilis, Nephrolepis cordifolia, and Senecio skirrhodon), and one from a cultivated plant of Metrosideros nervulosa. In the majority of genera the numbers follow established patterns. Counts have now been obtained for all known New Zealand representatives of the Alseuosmiaceae, Chloranthaceae, Dryopteridaceae, Elatinaceae, Euphorbiaceae, Geraniaceae, Hydatellaceae, Lauraceae, Linaceae, Rubiaceae, Scrophulariaceae, Nephrolepidaceae, Nyctaginaceae, Pandanaceae, Polypodiaceae, Sapotaceae, and Thelypteridaceae.
Article
Full-text available
Two new species of forget-me-nots, Myosotis chaffeyorum C.A.Lehnebach sp. nov. and Myosotis mooreana C.A.Lehnebach sp. nov. are described and illustrated. These species are endemic to New Zealand and restricted to the mountains of north-west Nelson (South Island). Both species are uncommon and Myosotis mooreana is known from the type locality only. Their conservation status is rated as "Nationally Critical". A table listing differences between these two new species and other similar species and an identification key are provided.
Article
Full-text available
The New Zealand hebes (Serophulariaceae) are members of a large Southern Hemisphere clade nested within Veronica. Analysis of ITS and rbcL sequences suggests that the New Zealand species are derived from a single common ancestor that arrived via long-distance dispersal. After the establishment of this initial founder population in New Zealand, the hebes have undergone at least two major episodes of diversification, giving rise to six clades. The great degree of morphological diversity in the New Zealand hebes contrasts with a corresponding low level of sequence divergence. New Zealand was a source of new emigrants to other regions in the South Pacific that were preadapted to high mountain, or forest margins. Our results suggest that two instances of long-distance dispersal from New Zealand to South America, at least one instance from New Zealand to Australia, and one instance from New Zealand to New Guinea have occurred relatively recently, Shorter hops to the Chatham Islands and the subantaretic islands are also supported by the sequence data
Article
Full-text available
Craspedia (Asteraceae: Gnaphalieac) is a genus of 23 species found only in Australia and New Zealand. Maxiinum parsimony arid maximum likelihood analyses of ITS and ETS intergenic spacers from the nuclear genome recovered three main lineages. The first lineage consists solely of the Australian species C. haplorrhiza, the relationships of which are unresolved, and the second includes species that are also exclusively Australian in distribution. The third lineage comprises two monophyletic groups; one including all the remaining Australian species sampled and the other, all New Zealand entities sampled. Monophyly of New Zealand Craspedia is also supported by analysis ofpsbA-trnH intergenic spacer sequences. Australian alpine species are independently derived from within the two larger Australian lineages. Both major Australian lineages are present in Tasmania suggesting multiple colonisations from mainland Australia. The single lineage of New Zealand Craspedia and the low divergences between Australian and New Zealand Craspedia samples are consistent with the derivation of New Zealand Craspedia via a single dispersal event from south-east Australia in the Late Tertiary or Quaternary. Compared with Australian Craspedia, the New Zealand species show extensive morphological divergence but little sequence divergence, suggesting a recent and rapid species radiation.
Article
Silicified nutlets of a Lithospermum from the Late Miocene Ash Hollow Formation of Bennett County, South Dakota, are described. Lithospermum dakotense sp. nov. shows similarities in size, shape, attachment, and epidermal cell patterns to extant Lithospermum species. Fossil nutlets were preserved in various stages of maturity. This is the first description of definite Lithospermum nutlets from Tertiary strata of North America.
Article
Cambridge Core - Natural Resource Management, Agriculture, Horticulture and forestry - Mabberley's Plant-book - by David J. Mabberley
Article
We investigate a neutral model for speciation and extinction, the constant rate birth-death process. The process is conditioned to have $n$ extant species today, we look at the tree distribution of the reconstructed trees-- i.e. the trees without the extinct species. Whereas the tree shape distribution is well-known and actually the same as under the pure birth process, no analytic results for the speciation times were known. We provide the distribution for the speciation times and calculate the expectations analytically. This characterizes the reconstructed trees completely. We will show how the results can be used to date phylogenies.
Article
Understanding the evolutionary history and biogeography of the New Zealand alpine flora has been impeded by the lack of an integrated model of geomorphology and climate events during the Late Miocene, Pliocene and Pleistocene. A new geobiological model is presented that integrates rock uplift age, rate of uplift and the resulting summit elevations in the Southern Alps (South Island) during the last 8.0 million years with a climate template using the natural gamma radiation pattern from the eastern South Island Ocean Drilling Program Site 1119 that covers the past 3.9 million years. This model specifically defines the average treeline in relation to mountain height, allowing predictions as to the timing of the formation of the alpine zone and other open habitats. This model predicts open habitats such as rock bluffs, tussock grasslands and riverbeds would have been available from about 4.0-3.0 Ma, coinciding with the initiation of summit uplift and a cooling climate providing an opportunity for the evolution of generalist alpine and open-habitat herbs and shrubs. Alpine habitats began to form at about 1.9 Ma and were a permanent feature of the Southern Alps from about 0.95 Ma. Specialist alpine plants confined to alpine habitats can have evolved only within this period once the alpine zone was persistent and widespread. Bog habitats are likely to date from the Late Miocene (c. 6.0 Ma), and the specialist bog species would have evolved from this time. Molecular-clock dates for DNA sequences from species of specialist alpine habitats, generalist open habitats, and bog habitats are consistent with predictions made on the basis of the model.
Article
Late Tertiary Valentine and Ash Hollow formations of the Ogallala Group in north-central Nebraska contain two previously unnamed fossiliferous ash-bearing members. These, with four published members, provide a stratigraphic framework for large collections of fossils in the Frick Collection in AMNH and other institutions. The Cornell Dam Member (New) in the basal Valentine Formation has salient lithic features and geologic relationships not found in other members of the Valentine. Basal channel sand disconformably overlying the Rosebud Formation contains macro- and microvertebrate fossils (Norden Fauna, New) that also show the ecological and faunal distinction of this member. Fission track dates suggest that Valentine sediments spanned one and perhaps three million years. The Merritt Dam Member (New), of late Clarendonian to late Hemphillian age, disconformably overlies the Cap Rock Member of the referred Ash Hollow Formation. The Merritt Dam Member is less cliff forming than the Cap Rock Member, contains more volcanic ash and local channel and pond sediments. Tectonic readjustment caused deep channel erosion through the Ogallala into Arikaree rocks on the east flank of the Chadron Arch and eastward into the Cap Rock Member and the Valentine Formation. Sediments filling some of these channels contain vertebrate fossils overlain by vitric tuffs with a fission track date of 9.5 ± 0.8 Ma. The paleogeomorphology of the Ogallala Group and its depositional framework is the product of overlapping alluvial fans of at least three paleodrainage systems which filled pre-existing valleys and spread sediments over a vast Great Plains area in Nebraska and South Dakota. In north-central Nebraska widespread aggradation and two short periods of degradation occurred during the Valentinian. Gradual aggradation during the early Clarendonian was followed by intermittent aggradation and degradation during the late Clarendonian and Hemphillian. The stratigraphic allocation and history of 98 collecting localities and documentation of 90 holotypes of fossil vertebrates and 13 plants provide a firm base for continued research. The principal aquifer in the Ogallala is the Crookston Bridge Member of the Valentine Formation.
Article
A 5-yr ongoing demographic study of the extremely localized (ca. 0.5 ha), rare, high-alpine endemic Myosotis oreophila and the widespread M. pulvinaris, where their ranges overlap, has revealed widely fluctuating populations in both species. Three representative permanent study plots totaling 290 m2 (6.4% of the total population area) were located near the center and on the margins of the M. oreophila population. High turnover rates have been confirmed by the loss of 1476 plants of M. oreophila and the recruitment of 1600 in the sample population over 5 yr. Three years of good recruitment and one of high mortality indicate that the total population of M. oreophila has varied by ca. 40%, from a maximum of ca. 21,800 to a minimum of ca. 13,000 plants over the 5-yr period. Thus it can be assumed that the whole population has essentially turned over in the 5-yr study period. The possible role of differential distribution of snowlie and/or snowmelt in this exposed high-alpine environment is being examined with experimental snow fences within and just beyond the limits of the M. oreophila population but monitoring of plant responses over the first 3 yr is inconclusive. The partially overlapping, but inversely related, distributions and density patterns of the leafy M. oreophila and cushion-forming M. pulvinaris have revealed similar demographic patterns and give no indication that either species is changing its status (i.e. advancing or retreating) along their respective margins. We tentatively endorse the rare status currently assigned to M. oreophila since the population, although extremely local, appears capable of maintaining itself despite a surprisingly rapid turnover of individual plants and the total population in a habitat where longevity of most of the high-alpine flora previously has been assumed.
Article
The "Alpine Ranunculi of New Zealand" are a monophyletic group of species distributed between the New Zealand alps, Australian alps, and the subantarctic Campbell and Auckland Islands. For this group we determined and analyzed sequences for the nuclear ITS and chloroplast JSA regions. This latter region was identified from an amplified fragment length polymorphism (AFLP) gel as being potentially phylogenetically informative. We have used quartet puzzling to represent the overall phylogenetic structure of these sequence data and split decomposition to investigate more closely the phylogenetic information among sequences from two lineages within the alpine radiation. We describe molecular evidence that shows that diversification of alpine Ranunculi has accompanied the onset of Pliocene mountain building in New Zealand, and that during range expansion of species, regional speciation into novel alpine habitats has occurred with parallel evolution of morphologies between more distantly related species. Our analyses also show that, during diversification and range expansion, the New Zealand alps acted as a center for long-distance dispersal to Australia and the New Zealand subantarctic islands.
Article
Distinguishing features of the fossil species of Cryptantha from the Pliocene Ogallala Formation are discussed. Comparisons are made to extant species where possible. Distributional ranges of the species are presented.
Article
The present study comprises an analysis of six different scoring schemes and eight different types of analytic methods aiming to investigate the evolution of a continuous character (i.e. corolla tube length) in Lithospermum L. (Boraginaceae). Corolla tube length in the genus is quite variable, ranging from 1 mm to 75 mm, and the length of the corolla tube has implications for pollination biology, such as longer corolla tubes (> 25 mm in length) being pollinated by hummingbirds or moths. In general, the various methods resolve similar ancestral character states; however, different states are reconstructed at nodes in which the descendants greatly differ in corolla tube length. Additionally, it is suggested that all of the variation of a continuous character should be included in analyses, and this may necessitate multiple analyses with different partitions of the data. The various analyses provide evidence that two maximum parsimony methods, linear parsimony and the TNT method, minimize the number of different rates of evolution. In Lithospermum, six origins of corolla tubes > 20 mm in length are resolved, and these origins occurred at two different times periods: (1) in the shadow of hummingbird diversification in North America (approximately 6–8 Mya) and (2) more recently (approximately 1–1.5 MyA). Four substantial decreases in corolla tube length also are reconstructed, and these may be associated with the origin of self‐pollination. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, ••, ••–••.
Article
Molecular sequence data have become increasingly used for examining the evolutionary history of plants at scales ranging from relationships among the major lineages of land plants to relationships within individual genera. Phylogenetic systematics has progressed ...
Article
... Regular Article. Phylogenetic Utility of the External Transcribed Spacer ( ETS ) of 18S – 26S rDNA : Congruence of ETS and ITS Trees ofCalycadenia ( Compositae ) *1. ...
Article
The phylogenetic relationships of Mertensia (Boraginaceae), which comprises approximately 45 species in both Asia and North America, have been uncertain, and taxonomists have placed the genus in various tribes of subfamily Boraginoideae, with the most recent placements in Trigonotideae and Cynoglosseae. Our study applies molecular phylogenetic methods to test the monophyly and relationships of Mertensia. We used DNA sequence data from the nuclear ribosomal nrlTS region and four cpDNA regions (matK, ndhF, rbcL, trnL-trnF) to examine the placement of Mertensia among a sampling of accessions from approximately 70% of the genera of Boraginaceae s. 1. Phylogeny reconstructions using maximum parsimony, maximum likelihood, and Bayesian inference were largely congruent with previous molecular phylogenetic analyses of Boraginaceae that had applied far fewer taxa. We recovered five deep clades that correspond to Boraginaceae subfamilies Boraginoideae, Cordioideae, Heliotropioideae, Hydrophylloideae, and Ehretioideae (including Lennoa and Pholisma). In subfamily Boraginoideae, we recovered clades that correspond to the tribes Echiochilieae, Lithospermeae, Cynoglosseae, and Boragineae, although several tribes previously circumscribed on the basis of morphological data were not recovered as monophyletic in our results. Based on the sister relationship between the genus Codon and subfamily Boraginoideae found in our phylogeny reconstructions, we propose Codoneae as a new tribe of Boraginoideae. We recovered strong support for the monophyly of Mertensia and the placement of the monotypic genus Asperugo as its sister. Mertensia and Asperugo were strongly supported as members of Cynoglosseae.
Article
Numerous molecular phylogenetic studies have used new biogeographic tools to explain species distributions. However, questions remain about origins, timing, direction of movement, and relationships between range expansion and diversification. We investigated geographic origins and temporal and spatial diversification of Mertensia, giving particular attention to divergence between Asian and North American lineages and radiation of western North American clades. Divergence time estimation and biogeographic analyses were based on phylogeny reconstruction inferred from nuclear ribosomal ITS and 12 plastid DNA sequence regions and a broad sampling of Mertensia, Boraginaceae, and core eudicots. MERTENSIA split from Asperugo in the late Oligocene to mid Miocene (26.83-12.22 million years ago [Ma]), followed by the first divergence in the crown group in the late Miocene (10.36-5.19 Ma). The ancestral area is inferred to have been Asia or a widespread distribution across Asia, Beringia, and circumboreal locales. Initial range expansion of North American Mertensia occurred in Beringia and the Pacific Northwest (7.70-4.22 Ma), followed by diversification of three clades (Pacific Northwest, southern Rocky Mountains, central Rocky Mountains). The crown divergence of extant Mertensia coincides with the onset of extreme cooling and fragmentation of a once extensive mixed mesophytic forest that was subsequently replaced by a boreal coniferous forest. Early diversification likely occurred when Beringia was connected and available for floristic exchange. The north-south orientation of the Rocky Mountain Range and Pleistocene glacial-interglacial cycles appear to have been important in the North American diversification of Mertensia.
Article
The evolutionary history of a set of taxa is usually represented by a phylogenetic tree, and this model has greatly facilitated the discussion and testing of hypotheses. However, it is well known that more complex evolutionary scenarios are poorly described by such models. Further, ...
Article
Species delimitation is of critical importance in systematics and biological and conservation research. The general-lineage species concept, which defines species as separately evolving metapopulation lineages, considers multiple lines of evidence to identify lineages and delimit species boundaries. Here, we apply the general-lineage concept to the New Zealand endemic Myosotis petiolata Hook.f. (Boraginaceae) species complex, to test its usefulness in the New Zealand Myosotis L. species radiation. We aimed to determine whether the complex contains separately evolving lineages to assess the criteria of monophyly, distinct genotypic clusters and fixed morphological differences by using amplified fragment length polymorphism (AFLP) and morphological data. The use of multiple criteria to identify separately evolving lineages within the M. petiolata complex was effective, but the different criteria were satisfied to varying degrees. Species rank is recommended for each of the currently recognised varieties as Myosotis pottsiana (L.B.Moore) Meudt, Prebble, R.J.Stanley & Thorsen (comb. & stat. nov.), M. pansa (L.B.Moore) Meudt, Prebble, R.J.Stanley & Thorsen (comb. & stat. nov.) and M. petiolata Hook.f. (North Island individuals only). A new allopatric subspecies, M. pansa subsp. praeceps Meudt, Prebble, R.J.Stanley & Thorsen (subsp. nov.), is also described. The distinguishing morphological characters and conservation status of each species are discussed. In addition, the low genetic diversity revealed in our population genetic analyses, coupled with few, fluctuating, disjunct populations, underscores the conservation priority of these three rare endemic New Zealand species.
Article
Myosotis brockiei Moore ct Simpson sp. nov., from the Cobb Valley—Mt Arthur area, is described and illustrated; it is compared with other Iong-stamened species with ebraetcate inflorescences in the subgenus Exarrhena.
Article
Lithospermum (Boraginaceae) comprises approximately 40 species in both the Old and New Worlds, with a center of diversity in the southwestern United States and Mexico. Using ten cpDNA regions, a phylogeny of Lithospermum and related taxa was reconstructed. Lithospermum (including New World and Old World species) and related New World members of Lithospermeae form a monophyletic group, with Macromeria, Onosmodium, Nomosa, Lasiarrhenum, and Psilolaemus nested among species of Lithospermum. New World Lithospermeae also is a monophyletic group, with Eurasian species of Lithospermum sister to this group. Because Lithospermum is not monophyletic without the inclusion of the other New World genera, species from these genera are transferred to Lithospermum, and appropriate nomenclatural changes are made. New combinations are Lithospermum album, Lithospermum barbigerum, Lithospermum dodrantale, Lithospermum exsertum, Lithospermum helleri, Lithospemum leonotis, Lithospermum notatum, Lithospermum oaxacanum, Lithospermum pinetorum, Lithospermum rosei, Lithospermum trinverium, and Lithospermum unicum; new names are Lithospermum chiapense, Lithospermum johnstonii, Lithospermum macromeria, Lithospermum onosmodium, Lithospermum rzedowskii, and Lithospermum turneri.
Article
Silicified nutlets of a Lithospermum from the Late Miocene Ash Hollow Formation of Bennett County, South Dakota, are described. Lithospermum dakotense sp. nov. shows similarities in size, shape, attachment, and epidermal cell patterns to extant Lithospermum species. Fossil nutlets were preserved in various stages of maturity. This is the first description of definite Lithospermum nutlets from Tertiary strata of North America. - Author
Article
Valdés, B.: The Euro+Med treatment of Boraginaceae. — Willdenowia 34: 59–61. — ISSN 0511-9618; © 2004 BGBM Berlin-Dahlem. The delimitation and tribal subdivision of the Boraginaceae are discussed, and a synonymic survey of the genera accepted for the purpose of the Euro+Med Project is presented. Three new combinations at subspecies rank are validated in the genera Aegonychon, Cynoglottis and Myosotis.
Article
To examine whether ecological traits associated with the New Zealand flora might influence species richness, I used published molecular phylogenies to compare traits associated with species richness of monophyletic groups in New Zealand and the relative species richness of New Zealand and their sister lineages. Species richness in New Zealand lineages tended to be lower than but not significantly different from their sister lineages. New Zealand lineages with fleshy fruits have lower numbers of species than their sister lineages, suggesting that regional differences in community processes can influence speciation or extinction. Lineages with sister taxa found exclusively on islands are characterised by low species richness both in New Zealand and elsewhere. In addition, species number was higher in insect‐pollinated New Zealand lineages than in wind‐ or bird‐pollinated lineages. There was no association with other correlates of mating system, including plant woodiness, gender dimorphism, and floral display. These results suggest that long‐distance dispersal, dependence on a biotic disperser or pollinator, and time since diversification all contribute to the species richness of a lineage.
Article
The biological and ecological significance of the “spring annual” life‐history strategy in the New Zealand flora is examined for Myosurus minimus subsp. novae‐zelandiae (Ranunculaceae), Ceratocephala pungens (Ranunculaceae), and Myosotis pygmaea var. minutiflora (Boraginaceae) in terms of their biogeographies, habitats, population sizes, seed morphologies, plant communities, and relationships with co‐occurring exotic taxa. All three have predominantly eastern South Island and lower North Island distributions, two have contracted modern ranges, and all extant populations are centred on Central Otago. The ephemeral wetland habitat of Myosurus, the “desert” pavement habitat of Ceratocephala, and the turf and gravel habitat surrounding water bodies of Myosotis all share a strong summer soil‐moisture deficit. These genuine non‐forest habitats are compared with farming‐induced scabweed or mat vegetation on dry hillslopes as additional facultative habitat for all three taxa. Selection for this growth strategy probably accompanied mountain building in the mid to late Cenozoic with the creation of seasonally dry eastern climates. Small numbers of sites, small population sizes, and habitat vulnerability to weeds and land conversion result in a conservation status of “threatened” for all three taxa. The problem of nesting conservation goals and management strategies for spring annual habitat within the restoration goals for their surrounding, degraded dryland ecosystems is highlighted.
Article
The relative amounts of self- and cross-pollen deposited on stigmas depends on both the number of pollinator visits that occur within plants and the amount of pollen carryover. Data collected for Myosotis colensoi (Kirk) Macbride and compiled from a survey of the literature, reveal that pollen carryover is frequently very high (upwards of 80%) and this at least partially relieves some of the effects of geitonogamous pollinator movements. It is suggested that in some cases, selection for traits that confer a high rate of pollen carryover may occur. Aspects of the plant–pollinator interaction that are likely to influence pollen carryover are discussed.
Article
We generated a genomic DNA library for Nothofagus solandri using 454 sequencing. Sequences from this library were screened for simple sequence repeat (microsatellite) motifs. Polymerase chain reaction (PCR) primer pairs were designed for 44 candidates and tested on a selection of samples collected from the wild. Seven of these PCR primer combinations produced interpretable polymorphic products. These have been assayed in 176 plants representing all the New Zealand species of Nothofagus subgenus Fuscospora (Nothofagus fusca, Nothofagus truncata and Nothofagus solandri). These markers will be applied to taxonomic, evolutionary and ecological studies of New Zealand beech.