The Genus Artemisia and its Allies: Phylogeny of the Subtribe Artemisiinae (Asteraceae, Anthemideae) Based on Nucleotide Sequences of Nuclear Ribosomal DNA Internal Transcribed Spacers (ITS)

Abstract: Sequences of the internal transcribed spacers (ITS1 and ITS2) of nuclear ribosomal DNA were analysed for 44 Artemisia species (46 populations) representing all the five classical subgenera and the geographical range of the genus, 11 species from 10 genera closely related to Artemisia, and six outgroup species from five other genera of the Anthemideae. The results definitely support the monophyly of the genus Artemisia in its broadest sense (including some taxa segregated as independent genera, like Oligosporus and Seriphidium ). Eight main clades are established in this molecular phylogeny within Artemisia; they agree in part with the classical subdivision of the genus, but they also suggest that some infrageneric groups must be redefined, especially the subgenus Artemisia. The subgenera Tridentatae and Seriphidium are independent from each other. Some of the satellite genera are clearly placed within Artemisia ( Artemisiastrum, Filifolium, Mausolea, Picrothamnus, Sphaeromeria, Turaniphytum ), whereas some others fall outside the large clade formed by this genus (Brachanthemum, Elachanthemum, Hippolytia, Kaschgaria). Our results, correlated to other data such as pollen morphology, allow us to conclude that the subtribe Artemisiinae as currently defined is a very heterogeneous group. Affinities of the largest genus of the subtribe and tribe, Artemisia, and of other genera of the subtribe to some genera from other subtribes of the Anthemideae strongly suggest that subtribe Artemisiinae needs a deep revision and redefinition. Phylogenetic utility of region trnL-F of the plastid DNA in the genus Artemisia and allies was also evaluated: sequences of the trnL-F region in Artemisia do not provide phylogenetic information.     

Leaf anatomy of the subtribe Conceveibinae (Euphorbiaceae)

A comparative study of the leaf anatomy of the subtribe Conceveibinae was carried out. Leaves show a similar structural arrangement in all species, however, there are small variations among the taxa that allow definitions of species or groups. It is not possible to recognize infrageneric divisions or to maintain some genera as different from Conceveiba. The analysis included the study of 11 characters of taxonomic importance of the leaf: the form, the size and the apex of the papillae of the lower side of the blade, the number of layers of the palisade parenchyma, the presence or absence of the midrib pith, the number of vascular bundles of petiole as well as the central cylinder and the medulla, and the presence or absence of the sclerenchyma in the different levels of the petiole. The results are evaluated from a taxonomical point of view. With leaf anatomy characters only, it is possible to separate the genus Conceveiba in the subtribe.     

Radiation in the Cape flora and the phylogeny of peacock irises Moraea (Iridaceae) based on four plastid DNA regions

Phylogenetic analyses of four plastid DNA regions, the rbcL exon, trnL intron, trnL-trnF intergenic spacer, and rps16 intron from each of 73 species in the African genus Moraea (Iridaceae: Irideae) including accessions of all major species clusters in the genus, show Moraea to be paraphyletic when Barnardiella, Galaxia, Hexaglottis, Homeria (all southern African), and Gynandriris (Eurasian as well) were recognized as separate genera. There are several small, isolated species clusters at the basal nodes of the tree that are all restricted to the winter-rainfall zone of southern Africa (the Greater Cape floral kingdom) and a few, highly derived, large species groups that have radiated extensively within the winter-rainfall zone. Mapping of floral traits shows that an Iris-type flower is ancestral in Moraea. Floral changes are associated with shifts in pollination systems, either from passive pollen deposition on long-tongued bees foraging for nectar to active pollen collection by female bees foraging for pollen, fly, or hopliine scarab beetle pollination. Dating the nodes of the phylogenetic tree using non-parametric rate smoothing with a calibration point derived from broad dating of the angiosperms indicates that the divergence between Moraea and its sister genus Ferraria occurred about 25 mya in the early Miocene. The early radiation of Moraea took place against a background of aridification and the spread of open habitats, such as desert, shrubland, and fynbos.     

Variation of DNA amount in 47 populations of the subtribe Artemisiinae and related taxa (Asteraceae, Anthemideae): karyological, ecological, and systematic implications.

Genome size has been estimated by flow cytometry in 47 populations of 40 species of the tribe Anthemideae (Asteraceae), mainly from Artemisia and other genera of the subtribe Artemisiinae and related taxa. A range of 2C values from 3.54 to 21.22 pg was found. DNA amount per basic chromosome set ranged from 1.77 to 7.70 pg. First genome size estimates are provided for one subtribe, 10 genera, 32 species, and two subspecies. Nuclear DNA amount correlated well with some karyological, physiological and environmental characters, and has been demonstrated as a useful tool in the interpretation of evolutionary relationships within Artemisia and its close relatives.     

Leaf anatomy of Bruniaceae: ecological, systematic and phylogenetic aspects

CARLQUIST, S., 1991. Leaf anatomy of Bruniaceae: ecological, systematic and phylogenetic aspects. Quantitative and qualitative data are given for 60 species of the 12 genera of Bruniaceae; most data are based on liquid-preserved material. Leaves of Bruniaceae are basically linear (broader forms are probably derived) with an apicula that contains phellogen activity. Most bruniaceous leaves have some degree of isolateral construction, with transition to normal bifacial construction in a few species, but more commonly transition to 'inverse' bifacial structure (stomata on adaxial face, palisade on abaxial face). The latter type is correlated with the tendency for leaves to be appressed to stems. Tannins and very likely other dark-staining materials are very characteristic of mesophyll cells. Six genera have a large strand of fibres on the midvein and rhomboidal crystals in bundle sheath cells. The other six genera have few or no fibres on veins and have druses in mesophyll cells (but not in bundle sheath cells). These distinctions may relate to intrafamilial taxonomy, but they also support the primitive position usually accorded to Audouinia, Thamnea and Tittmannia. A key to genera based on leaf antomy is offered. Details of epidermal cell shape, cuticular relief and trichome form and structure based on scanning electron microscopy are given. Leaf anatomy, combined with other features, favours a relationship between Bruniaceae and Grubbiaceae in particular and in broader contexts allies Bruniaceae to rosalean and possibly hamamelidalean families.     

Leaf anatomy of the genus Psoralea sensu stricto (Psoraleeae, Papilionoideae, Leguminosae)

Leaf anatomy is described from 17 species of Psoralea sensu stricto which includes four species of the genus Hallia Thunberg. Species of the two genera share many characters including the presence of rod-shaped crystals, similar stipule structure and a possible continuum in secretory cavity anatomy ranging from a small and non-trabeculate to a large and trabci ulate form. Hallia species are distinguished b the presence of large tannin cells in the bundle sheaths and a narrow lcngllv.width ratio of palisade cells. In the light of other floral evidence this is considered insufficient to separate the two genera, a view confirmed by cluster analysis. Thus, Salter's proposal of 1939 for their amalgamation is supported. Leaf anatomy of herbaceous species is compared with that of seedlings of Psoralea sp. to assess the possibility that the herbaceous species may have arisen through neoteny from species that are trees or shrubs. Comparative venation studies between stipules and scale leaves suggest that the scale leaf form arose from pinnate-leaved ancestors by leaf reduction.     

Phylotranscriptomics of Swertiinae (Gentianaceae) reveals that key floral traits are not phylogenetically correlated

Establishing how lineages with similar traits are phylogenetically related remains critical for understanding the origin of biodiversity on Earth. Floral traits in plants are widely used to explore phylogenetic relationships and to delineate taxonomic groups. The subtribe Swertiinae (Gentianaceae) comprises more than 350 species with high floral diversity ranging from rotate to tubular corollas and possessing diverse nectaries. Here we performed phylogenetic analysis of 60 species from all 15 genera of the subtribe Swertiinae sensu Ho and Liu, representing the range of floral diversity, using data from the nuclear and plastid genomes. Extensive topological conflicts were present between the nuclear and plastome trees. Three of the 15 genera represented by multiple species are polyphyletic in both trees. Key floral traits including corolla type, absence or presence of lobe scales, nectary type, nectary position, and stigma type are randomly distributed in the nuclear and plastome trees without phylogenetic correlation. We also revealed the likely ancient hybrid origin of one large clade comprising 10 genera with diverse floral traits. These results highlight the complex evolutionary history of this subtribe. The phylogenies constructed here provide a basic framework for further exploring the ecological and genetic mechanisms underlying both species diversification and floral diversity.     

Vegetative anatomy and systematics of subtribe Dendrobiinae (Orchidaceae)

Anatomy of leaf, stem, and root of more than 100 species in subtribe Dendrobiinae (Orchidaceae) was studied with the light microscope to provide a comparative anatomical treatment of these organs, to serve as an independent source of evidence that might be taxonomically important, and to recommend such reinterpretations of existing classifications as are suggested by a phylogenetic assessment of data. We based our classification on that of Rudolf Schlechter as the most complete and widely accepted today. We found that the anatomy of plants in subtribe Dendrobiinae reflects a high degree of morphological diversity, and many of the anatomical characters appear to be homoplasous. When these anatomical data are used to interpret the systematic relationships among the genera, they indicate that Dendrobium is not monophyletic and that Cadetia and Pseuderia are apparently nested within the structure of Dendrobium when section Grastidium is chosen as a functional outgroup. Lack of resolution in the strict consensus tree illustrates the difficulty of determining the phylogenetic relationships of many of Schlechter's sections using anatomical characters. Nevertheless, we recommend that his sectional classification, with appropriate modifications based on available data, be retained for the present, pending a more detailed understanding of the phylogeny of Dendrobiinae based on morphology, micromorphology, anatomy, and DNA studies.     

Flower anatomy of the subtribe Hyptidinae (Labiatae)

Flowers of 34 species, representing 4 of the 6 genera of the morphologically diverse South American subtribe Hyptidinae and including members of many of the sections of the genus Hyptis are investigated. Floral anatomy is basically uniform, with some minor variations which are mainly related to differences in flower size. Marsypianthes differs from the other genera in that the style is fused to the ovary, the hypogynous disc is relatively massive, and there are 12 or 13 calyx traces rather than the usual number of 10. The stylopodium, which is characteristic of Eriope and certain sections of Hyptis, is a fold of stylar tissue which develops in the bud prior to opening of the flower and is probably an abscission layer.     

Molecular systematics and biogeography of Crawfurdia, Metagentiana and Tripterospermum (Gentianaceae) based on nuclear ribosomal and plastid DNA sequences

BACKGROUND AND AIMS: The systematic position of the genus Metagentiana and its phylogenetic relationships with Crawfurdia, Gentiana and Tripterospermum have not been explicitly addressed. These four genera belong to one of two subtribes (Gentianinae) of Gentianeae. The aim of this paper is to examine the systematic position of Crawfurdia, Metagentiana and Tripterospermum and to clarify their phylogenetic affinities more clearly using ITS and trnL intron sequences. METHODS: Nucleotide sequences from the internal transcribed spacers (ITS) of nuclear ribosomal DNA and the plastid DNA trnL (UAA) intron were analysed phylogenetically. Ten of fourteen Metagentiana species were sampled, together with 40 species of other genera in the subtribe Gentianinae. KEY RESULTS: The data support several previously published conclusions relating to the separation of Metagentiana from Gentiana and its closer relationships to Crawfurdia and Tripterospermum based on studies of gross morphology, floral anatomy, chromosomes, palynology, embryology and previous molecular data. The molecular clock hypothesis for the tested sequences in subtribe Gentianinae was not supported by the data (P < 0.05), so the clock-independent non-parametric rate smoothing method was used to estimate divergence time. This indicates that the separation of Crawfurdia, Metagentiana and Tripterospermum from Gentiana occurred about 11.4-21.4 Mya (million years ago), and the current species of these three genera diverged at times ranging from 0.4 to 6.2 Mya. CONCLUSIONS: The molecular analyses revealed that Crawfurdia, Metagentiana and Tripterospermum do not merit status as three separate genera, because sampled species of Crawfurdia and Tripterospermum are embedded within Metagentiana. The speciation and rapid radiation of these three genera is likely to have occurred in western China as a result of upthrust of the Himalayas during the late Miocene and the Pleistocene.     

Phylogenetic relationships of subtribe Ecliptinae (Asteraceae: Heliantheae) based on chloroplast DNA restriction site data

Phylogenetic analysis of chloroplast DNA restriction site data for 76 of the 302 genera of Heliantheae sensu lato using 16 restriction endonucleases reveals that subtribe Ecliptinae is polyphyletic and that its genera are distributed in four different lineages. The ecliptinous genera Squamopappus, Podachaenium, Verbesina, and Tetrachyron (of the Neurolaeninae), along with other members of subtribe Neurolaeninae are the basalmost clades of the paleaceous Heliantheae. The mostly temperate species of subtribe Ecliptinae (exemplified by Balsamorhiza, Borrichia, Chrysogonum, Engelmannia, Silphium, Vigethia, and Wyethia) are strongly nested in a clade with the Mesoamerican monotypic genus Rojasianthe as basal. The genera characterized by marcescent ray corollas traditionally classified in subtribe Zinniinae constitute a strongly supported group sister to Acmella, Spilanthes, and Salmea. The largest clade of ecliptinous genera is the most recently derived group within Heliantheae sampled. This large group of mostly Neotropical lowland genera (variously characterized by their winged cypselae, foliaceous phyllaries, and opposite phyllotaxy and exemplified by Perymenium, Wedelia, and Zexmenia) has been and continues to be the most challenging group from a taxonomic standpoint. The study provides new insights as to their relationships that will have a positive impact in future monographic studies of the group. The genera of the Espeletiinae form a monophyletic clade and are sister to members of the Milleriinae and Melampodiinae. This result is consistent with their traditional taxonomic placement with genera such as Smallanthus with which they share a tendency for functionally staminate disc flowers. The phylogenetically enigmatic genus Montanoa is sister to Melampodium. Members of subtribe Galinsoginae are clustered in two main lineages that correspond to the traditional division of the subtribe based on pappus characteristics. There is no support for the monophyly of subtribe Galinsoginae, and the same results indicate some of its genera are paraphyletic.     

Leaf anatomy and relationships of Dietes (Iridaceae)

The leaf anatomy of Dietes is described, including all 6 species. Characters support the morphological evidence that Dietes is a distinct genus and related to other Iridoideae. Certain features, notably the epidermal structure and sheath vasculature, distinguish it from other Iridaceous genera, although the sheath vasculature indicates a relationship with some New World Iridoideae. The leaf margin type is similar to that of other Old World Iridoideae. Many leaf anatomical characters in Dietes are associated with xeromorphy. Leaf anatomy supports the division of Dietes into 2 subgenera.     

Taxonomic separation of the genera Prosthechea and Encyclia (Laeliinae: Orchidaceae) using leaf and root anatomical features

Despite formal separation based on molecular and morphological evidence, the genera Prosthechea Knowles & Westc. and Encyclia Hook. have not been studied in terms of their vegetative anatomy. In this study we examine 16 Brazilian species of these genera. Additionally, one species of subtribe Laeliinae and another from subtribe Oncidiinae were studied in order to evaluate the taxonomic consistency of the anatomic characters observed. Except for Epidendrum crassifolium Lindl., all species possess a velamen differentiated into epivelamen and endovelamen. Endodermal cells with uniformly thickened walls, calcium oxalate raphides and cells with phi thickenings in the cortical region were observed in all species. Silica bodies, raphides and fibre bundles in the mesophyll were common in leaves of all species studied. By contrast, flavonoid crystals were observed in both roots and leaves of Prosthechea only. Encyclia is characterized by the presence of fibre bundles on the subepidermal layer, and a cuticle, which is clearly thicker than that of Prosthechea . These data strongly support the separation of Prosthechea and Encyclia .  © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society , 2003, 143 , 293–303.     

Anatomía comparativa de la lámina foliar y sistemática en la subtribu neotropical Mauritiinae (Arecaceae,Calamoideae)

This represents the first comparative study of the leaf anatomy within the subtribe Mauritiinae (Arecaceae) and includes all three genera and most of the recognized species. The leaf blade anatomy clearly defines these neotropical palms and allows the identification of two groups: Lepidocaryum can be separated by its homogeneous mesophyll, while the group formed by Mauritia y Mauritiella has the shared presence of a diferentiated mesophyll into palisade and spongy parenchyma. Our study supports the topologies of the most recent molecular phylogenies that include these three genera; however we did not identify characters that are sufficiently variable for species identification.     

Leaf anatomy in the Tecophilaeaceae

ARROYO, S., 1986. Leaf anatomy in the Tecophilaeaceae . Leaf anatomy of 12 species of the seven genera in the Tecophilaeaceae is described. Characters of taxonomic value within the family are the shape of epidermal cells, hairs and venation. Characters of diagnostic importance at the family level include the occurrence of raphide sacs in the mesophyll, the absence of vessels in the aerial part of the plant and the presence of anomocytic stomata. Leaf anatomy is of restricted value within the family but supports the retention of both Cyanastrum and Walleria within the Tecophilaeaceae.     

Phylogeny of the Spiny African Daisies (Compositae, tribe Arctotideae, subtribe Gorteriinae) based on trnL-F, ndhF, and ITS sequence data

The tribe Arctotideae (African Daisies), of the flowering plant family Compositae (Asteraceae), is a diverse and interesting group with a primarily southern African distribution (ca. 13 genera, 215 species) and many species in the Cape Floristic Region. It is divided into two subtribes: Arctotidinae (ca. 5 genera, 85 species) and Gorteriinae (ca. 8 genera, 130 species). The monophyly of the genera within the subtribe Gorteriinae and their relationship to one another was investigated using 71 samples/212 sequences including 64/141 of which are newly reported from three phylogenetic markers, two from chloroplast DNA (trnL-F and ndhF) and one from the nuclear genome (ITS). The outgroup was composed of seven members from the sister subtribe. Results show the subtribe Gorteriinae to be divided into three monophyletic groups, the Gazania-Hirpicium-Gorteria group, the Didelta group, and the Berkheya-Cullumia group. Within these three groups are 13 sub-groups, one of which has sub-clades. The genus Berkheya Ehrh. is paraphyletic, falling into five different sub-groups. The two monotypic genera, Cuspidia and Heterorhachis are not nested within any of the Berkheya clades. Hirpicium and Cullumia each have most of their taxa in a monophyletic group, but they also have one or two taxa associated with other clades. Four of the five sub-groups of Berkheya have morphologically recognizable shared characters, such as habit and spines that have been recognized by past studies. However, the grouping of one species with Didelta is difficult to explain. Support for the major clades and most of the sub-groups is strong but the relationships among some of the terminal taxa are variable.     

New or rarely reported chromosome numbers in taxa of subtribe Artemisiinae (Anthemideae, Asteraceae) from Mongolia

This study encompasses 25 chromosome counts of 18 species in the subtribe Artemisiinae (tribe Anthemideae) of the family Asteraceae, from Mongolia. Most (15 species) belong to Artemisia , the largest genus of the subtribe, whereas the others come from two genera very closely related to it: Ajania (two species) and Neopallasia (one species). Eleven counts are new reports, three are not consistent with previous reports and the remainder confirm scanty earlier information. The majority of the species have x  = 9 as their basic chromosome number, but there are some taxa with x  = 8. Ploidy levels range from 2 x to 6 x . The presence of B-chromosomes was detected in Ajania fruticulosa .  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 150 , 203–210.     

Flavonol diglycosides from Blackstonia perfoliata.

Two unusual diglycosides, quercetin and kaempferol 3-rhamnosyl(1----2)galactosides and the new isorhamnetin 3-rhamnosyl(1----2)galactoside have been isolated from the aerial parts of Blackstonia perfoliata. Instead of C-glycosylflavones, the occurrence of flavonol glycosides in this species as well as in three other genera of the Gentianaceae: Centaurium, Coutoubea and Eustoma, is in agreement with the grouping of these four genera in the subtribe Chlorae of the Gentianeae.     

Pericarp structure and phylogeny within Lamiaceae subfamily Nepetoideae tribe Ocimeae

The pericarp structure has been investigated in about 205 species, representing 43 out of the about 50 genera of Lamiaceae subfamily Nepetoideae tribe Ocimeae (Ocimoideae). In its basic structure, the pericarp of Ocimeae corresponds to that of other Nepetoideae. The exocarp has usually both mucilaginous and non-mucilaginous cells. Below it, there are soft cells (mesocarp), a layer of vertically arranged bone cells and a thin innermost cell layer. The differences discovered in pericarp anatomy essentially agree with the traditional subdivisions of Ocimeae (by e.g. Briquet). The subtribes Hyptidinae and Ociminae and the genus Aeollanthus (in subtribe Plectran-thinae) have, with few exceptions crystals in the bone cells. Unlike other Labiatae, Plectranthinae (except Alvesia, Isodon and Siphocranion ) has a plate-like content in the mucilaginous cell. The systematic position of the latter three genera is discussed. Because of their pericarp anatomy, Hoslundia, Fuerstia, Catoferia, Nosema, Benguellia, Octomeron and Ceratanthus are suggested to belong to Ociminae, and Neohyptis to Plectranthinae. On the basis of pericarp characters an informal division of Ociminae is suggested. Considering the distribution of stamen and pericarp characters, the genera Capitanya, Pycnostachys and Solenostemon are suggested to originate from Plectranthus. Ocimeae species which grow in arid habitats tend to produce more mucilage and to have a larger plate-like content in the mucilaginous cells than species from moist or wet habitats.