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Abstract

Linum bicolor is a problematic North African taxon associated with L. setaceum. A consensus on the taxonomic status of a putative form (L. setaceum var. bicolor f. robusta) has not been achieved yet. We conducted a morphological study based on herbarium and field collections, combined with nuclear (ITS) and plastid (ndhF5-8 and trnL-F) phylogenies to clarify its status. The phylogenetic analysis did not reveal molecular divergence, but a comparative morphological study revealed substantial differences in traits previously used to distinguish the two taxa (stems, leaves, corolla and calyx size). In addition, we found that the indumentum of sepals, petal colour, and the arrangement of anthers and stigmas differed so clearly between the form robusta and L. setaceum s. stricto, further supporting the former taxon as an independent species. We provide an identification key to the yellow- and white-flowered Linum species in NW Africa. We also revised the unplaced name L. bicolor Schoubs. ex DC.and lectotypified it to avoid nomenclatural problems.
... The present study based on the sampled species revealed that the section Linum is monophyletic, while two sections Linastrum and Syllinum are paraphyletic. Paraphyly of the sections within the genus Linum, was also reported by the others (Savolainen et al. 2000, McDill et al. 2009, Ruiz-Martín et al. 2015. ...
... (L opez Gonz alez 1979;Mart ınez-Labarga & Mu~ noz-Garmendia 2015), with a special case of three-dimensional reciprocity ( Armbruster et al. 2006), L. tenue, a polyphyletic species with substantial morphological variation in NW Africa (J. Arroyo and J. Ruiz-Mart ın, personal observations), as well as a recently named new distylous species, L. flos-carmini ( Ruiz-Mart ın et al. 2015), different from its sister homostylous L. setaceum. All this variation clearly reflects that further work is required in these taxa and geographic ranges. ...
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Heterostyly is a sex polymorphism that has challenged evolutionary biologists ever since Darwin. One of the lineages where heterostyly and related stylar conditions appear more frequently is Linum (Linaceae). This group is particularly suitable for testing competing hypotheses about ancestral and transitional stages on the evolutionary building up of heterostyly. We generated a phylogeny of Linum based on extensive sampling and plastid and nuclear DNA sequences, and used it to trace the evolution of character states of style polymorphism. We also revised available data on pollination, breeding systems, and polyploidy to analyse their associations. Our results supported former phylogenetic hypotheses: the paraphyly of Linum and the non-monophyly of current taxonomic sections. Heterostyly was common in the genus, but appeared concentrated in the Mediterranean Basin and the South African Cape. Ancestral character state reconstruction failed to determine a unique state as the most probable condition for style polymorphism in the genus. In contrast, approach herkogamy was resolved as ancestral state in some clades, giving support to recent hypotheses. Some traits putatively related to heterostyly, such as life history and polyploidy, did show marginal or non-significant phylogenetic correlation, respectively. Although pollinator data are limited, we suggest that beeflies are associated with specific cases of heterostyly. The consistent association between style polymorphism and heteromorphic incompatibility points to ecological factors as drivers of the multiple evolution of style polymorphism in Linum. Albeit based on limited evidence, we hypothesised that specialised pollinators and lack of mating opportunities drive evolution of style polymorphism and loss of the polymorphism, respectively.
... the genus Linum linnaeus (1753: 277) comprises about 200 species distributed in temperate and tropical regions of the world, including the cultivated L. usitatissimum linnaeus (1753: 277) and some garden ornamentals (McDill et al. 2009). the Mediterranean area is one of the main centers of diversity for this genus, including about the half of the known taxa (Yilmaz & Kaynak 2008, tugay et al. 2010, Peruzzi 2011, Ruiz-Martín et al. 2015. ...
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Linum elegans has been detected in calcareous rocky garrigues on the Gargano promontory (Apulia, SE-Italy), representing the first record for the Italian flora and the first one outside the Balkan Peninsula. The geographical disjunction may provide evidence for past amphi-Adriatic/amphi-Ionic terrestrial connections. The population found was ascribed to L. campanulatum in the past. As a consequence, a comparison between these two species is undertaken. Furthermore, the name L. elegans is here lectotypified on a specimen preserved at G, and the IUCN assessment of the species in Italy is briefly discussed.
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The genus Linum Linnaeus (1753: 277) consists of about 200 species distributed in temperate and tropical regions of the world. The Mediterranean area can be considered one of the centers of diversity of this genus (Greuter et al. 1989, Yilmaz et al. 2003, Yilmaz & Kaynak 2008, 2010, Tugay et al. 2010, Peruzzi 2011, Ruiz-Martin et al. 2015).
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Six primers for the amplification of three non-coding regions of chloroplast DNA via the polymerase chain reaction (PCR) have been designed. In order to find out whether these primers were universal, we used them in an attempt to amplify DNA from various plant species. The primers worked for most species tested including algae, bryophytes, pteridophytes, gymnosperms and angiosperms. The fact that they amplify chloroplast DNA non-coding regions over a wide taxonomic range means that these primers may be used to study the population biology (in supplying markers) and evolution (inter- and probably intraspecific phylogenies) of plants.
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The main features of the phylogeny program TNT are discussed. Windows versions have a menu interface, while Macintosh and Linux versions are command-driven. The program can analyze data sets with discrete (additive, non-additive, step-matrix) as well as continuous characters (evaluated with Farris optimization). Effective analysis of large data sets can be carried out in reasonable times, and a number of methods to help identifying wildcard taxa in the case of ambiguous data sets are implemented. A variety of methods for diagnosing trees and exploring character evolution is available in TNT, and publication-quality tree-diagrams can be saved as metafiles. Through the use of a number of native commands and a simple but powerful scripting language, TNT allows the user an enormous flexibility in phylogenetic analyses or simulations. © The Willi Hennig Society 2008.
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Fourteen native species of Linum are recognized in southern Africa, all of which belong to sect. Linopsis. Four are commonly accepted species; four were described more than a century ago but have not been recognized in recent treatments; six are newly described. Thirteen species are endemic; one ranges as far north as Angola and Tanzania. Among the new species two are heterostylous, the first described for the genus from this region.The section Linopsis ranges broadly from the Mediterranean region to southern Africa and to both North and South America. The occurrence in the Mediterranean region of species exhibiting such features as heterostyly and chromosome numbers of 2n = 18 or 20, the only diploids known in the section, seems to indicate that in that region are to be found the most primitive species of the section. The close similarity between species of southern Africa and a number of South American and North American species appears to place the southern African species in an intermediate evolutionary position with respect to the Old and New World species of the section.
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The phylogeny of Linaceae is examined, with sampling from the 13 commonly recognized genera of the family and sequence data from the plastid genes matK and rbcL. Representatives of 24 additional families of the order Malpighiales are included in the analyses, with members of Celastrales, Fabales, Fagales, Oxalidales and Rosales used as outgroups. Linaceae and both subfamilies, the temperate Linoideae and the tropical Hugonioideae, are found to be monophyletic in likelihood- and parsimony-based analyses, although the monophyly of Hugonioideae is not well supported. Average divergence time estimates using rbcL indicate that the subfamilies diverged from each other during the Palaeocene, approximately 60 million years ago. No sister group to Linaceae is consistently identified in these analyses, and relationships among families of Malpighiales are not well resolved. In accord with previous estimates of Linoideae phylogeny, Linum is shown to be nonmonophyletic, with several segregate genera nested within it, but the relationships of the south-east Asian genera, Anisadenia, Reinwardtia and Tirpitzia, remain uncertain. In Hugonioideae, Indorouchera and Philbornea are found to be closely related to members of Hugonia section Durandea. Relationships of the neotropical genera Hebepetalum and Roucheria to the palaeotropical hugonioids are not consistently resolved. © 2010 The Linnean Society of London, Botanical Journal of the Linnean Society, 2011, 165, 64–83.