19 research outputs found

    A worldwide molecular phylogeny and classification of the leafy spurges, Euphorbia subgenus Esula (Euphorbiaceae)

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    The leafy spurges, Euphorbia subg. Esula, make up one of four main lineages in Euphorbia. The subgenus comprises about 480 species, most of which are annual or perennial herbs, but with a small number of dendroid shrubs and nearly leafless, pencilâ stemmed succulents as well. The subgenus constitutes the primary northern temperate radiation in Euphorbia. While the subgenus is most diverse from central Asia to the Mediterranean region, members of the group also occur in Africa, in the Indoâ Pacific region, and in the New World. We have assembled the largest worldwide sampling of the group to date (273 spp.), representing most of the taxonomic and geographic breadth of the subgenus. We performed phylogenetic analyses of sequence data from the nuclear ribosomal ITS and plastid ndhF regions. Our individual and combined analyses produced wellâ resolved phylogenies that confirm many of the previously recognized clades and also establish a number of novel groupings and placements of previously enigmatic species. Euphorbia subg. Esula has a clear Eurasian center of diversity, and we provide evidence for four independent arrivals to the New World and three separate colonizations of tropical and southern Africa. One of the latter groups further extends to Madagascar and New Zealand, and to more isolated islands such as Réunion and Samoa. Our results confirm that the dendroid shrub and stemâ succulent growth forms are derived conditions in E. subg. Esula. Stemâ succulents arose twice in the subgenus and dendroid shrubs three times. Based on the molecular phylogeny, we propose a new classification for E. subg. Esula that recognizes 21 sections (four of them newly described and two elevated from subsectional rank), and we place over 95% of the accepted species in the subgenus into this new classification.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146962/1/tax6221.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146962/2/tax6221-sup-004-pdf.pd

    Phylogenetic placement of Stachys sect. Satureoides (Lamiaceae; Lamioideae)

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    Stachys sect. Satureoides includes four species characterized by being annual herbs having oblanceolate leaves, urceolate calyx in fruit and dense hairs at mouth and are distributed from Eastern and Southern Turkey, Syria, Northern Iraq to Western Iran. The main aim of present study is to determine the phylogenetic placement of S. sect. Satureoides based on Stachys melampyroides, as the only representative of this section in Iran. The present molecular study was conducted based on nuclear ribosomal ITS marker, using Maximum Parsimony and Bayesian Inference analyses. In total, 86 accessions (including nine outgroups and 77 ingroups) were included. Our results demonstrated that sect. Satureoides was placed in Olisia clade which is one of the most heterogenous and taxonomically challenging clades of Stachys as a paraphyletic genus. Moreover, not only sect. Satureoides was not found to be phylogenetically close to sect. Neurocalyx, as had been suggested by previous morphological studies, but also it was placed as a sister group of sect Fragilicaulis which was characterized by chasmophilus species with fragile stems and yellow flowers. Our results revealed that sect. Neurocalyx could be the closest group to the Satureoides+Fragilicaulis clade. In addition, based on the nrITS phylogenetic tree, annual species of Stachys showed affinity to perennial Stachys species. Hence, it seems that “Annual habit” have been evolved among their perennial ancestors, independently

    Nutlet micromorphology and its systematic implications in Phlomoides Moench (Lamiaceae)

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    Nutlets of 20 taxa of Phlomoides, representing most of the currently recognized sections were examined by scanning electron microscopy. The basic shape of nutlets in most taxa studied is broadly ovate, but ovate, triangular and oblong ones can also be found in few species. Regarding the sculpturing pattern of nutlet surface, four basic types can be distinguished: reticulate, scalariform, ruminate and rugose. The reticulate type is the most common among the studied species, but the variation in alignment, size and shape of its composing cells provide further evidence that are useful as diagnostic characteristics. However, the type of sculpturing is more useful for separating species within the sections, rather than correlating them to each other. For example, sect. Filipendula show four different types of sculpturing. Therefore, nutlet microsculpturing is not useful in separating large natural groups like sections in this genus. It seems also that contrary to other genera of Lamiaceae, nutlet characters are of low phylogenetic value in this genus

    from northeastern Iran

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    Phlomoides binaludensis (Phlomideae, Lamioideae, Lamiaceae), a new specie

    Ancestral state reconstruction reveals extensive homoplasy in nutlet characters of Cynoglossinae (Boraginaceae, subfam. Cynoglossoideae, tribe Cynoglosseae)

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    Recent phylogenetic studies have challenged the traditional classification of the subtribe Cynoglossinae, which was based on nutlet characteristics. To investigate the evolution of fruit traits related to dispersal modes in this complex group, we conducted a study using scanning electron microscopy to examine 28 taxa representing all previously recognized lineages of the subtribe. Cynoglossinae displays four main types of nutlets: marginate, emarginate, flat wing, and incurved wing. Our findings reveal the arrangement of glochids and their structure, including the number of apical hooks, and their surface ornamentation is highly variable both across and within these four main types. We reconstructed the phylogenetic tree with four main clades (i.e., Clades I–IV) using Maximum likelihood analysis. In addition, we mapped four nutlet traits (i.e., nutlet margin, nutlet glochid, glochid sculpture, and glochid hooks) associated with different dispersal modes using ancestral state reconstruction analysis. The ancestor of subtribe Cynoglossinae was inferred to have marginate and glochidiate nutlets, with glochids externally provided with complex spiny tubercles and bearing at least four hooks at the tip as well as epizoochory dispersal mode. These ancestral states have been retained in Clade II (East Asian-Australian-African Cynoglossum-Lindelofia clade) and Clade III (Mediterranean-Asian Cynoglossum-Solenanthus-Trachelanthus clade), with several independent shifts to emarginate fruits. Transitions from marginate to wide-winged nutlets have occurred at least four independent times, facilitating wind-assisted dispersal in Clade I (Microparacaryum clade), Clade IV (Paracaryum-Mattiastrum-Rindera clade), Rindera tetraspis, and Mattiastrum crista-galli (both belonging to Clade III), where a transition from tuberculate to papillate surface has also occurred.</p
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