La fougère Diplazium proliferoides Bory, une espèce d'origine hybride (Polypodiales : Athyriaceae)

Résumé : Dans la Flore des Mascareignes, Badré (2008) a traité le nom Diplazium proliferoides Bory en synonymie de D. proliferum (Lam.) Thouars, soulignant toutefois que la dissection des frondes de ces deux taxons est différente : D. proliferum a des frondes pennées alors que D. proliferoides a des frondes bipinnatifides à bipennées. Nous montrons dans cette étude, grâce à des données cytologiques et biométriques sur les stomates, que D. proliferoides est d’origine hydride, ayant D. proliferum et D. arborescens Bory (Sw.) pour parents putatifs. Nous confirmons également, grâce à nos mesures sur des échantillons provenant de l’Herbier national de Paris (P), la présence ancienne de D. arborescens et de D. proliferoides à l’île Maurice. Abstract : In the Flore des Mascareignes, Badré (2008) has treated the name Diplazium proliferoides Bory as synonymy of D. proliferum Lam. Thouars emphasized that the fronds dissection of both taxa were different : D. proliferum has pinnate fronds whereas D. proliferoides has bipinnatid to bipinnate fronds. We show here, through cytological and biometric data on stomata, that D. proliferoides has an hybrid origin with D. proliferum and D. arborescens Bory (Sw.) as putative parents. We also confirm, using specimens from the Herbarium of Paris (P), the historical presence of both D. arborescens and D. proliferoides on Mauritius

Systematic Revision of Elaphoglossum (Dryopteridaceae) in French Polynesia, with the Description of Three New Species

Species descriptions and a key for the nine species of Elaphoglossum (Dryopteridaceae) in French Polynesia are provided. Three new species are described: E. austromarquesense from the southern Marquesas Islands, E. florencei from Raiatea and Moorea, and E. meyeri from Rapa. Each species is illustrated by a line drawing of the habit, and spore images using a scanning electron microscope. Images of scales, one of the most important diagnostic characters in the genus, are also included. © 2008 The Linnean Society of London

European Red List of Lycopods and Ferns

Peer reviewe

Human-Mediated Emergence as a Weed and Invasive Radiation in the Wild of the CD Genome Allotetraploid Rice Species (Oryza, Poaceae) in the Neotropics

BACKGROUND: The genus Oryza is being used as a model in plant genomic studies although there are several issues still to be resolved regarding the spatio-temporal evolution of this ancient genus. Particularly contentious is whether undated transoceanic natural dispersal or recent human interference has been the principal agent determining its present distribution and differentiation. In this context, we studied the origin and distribution history of the allotetraploid CD rice genome. It is endemic to the Neotropics but the genus is thought to have originated in the Paleotropics, and there is relatively little genetic divergence between some orthologous sequences of the C genome component and their Old World counterparts. METHODOLOGY/PRINCIPAL FINDINGS: Because of its allotetraploidy, there are several potential pitfalls in trying to date the formation of the CD genome using molecular data and this could lead to erroneous estimates. Therefore, we rather chose to rely on historical evidence to determine whether or not the CD genome was present in the Neotropics before the arrival of Columbus. We searched early collections of herbarium specimens and studied the reports of explorers of the tropical Americas for references to rice. In spite of numerous collectors traveling inland and collecting Oryza, plants determined as CD genome species were not observed away from cultivated rice fields until 1869. Various arguments suggest that they only consisted of weedy forms until that time. CONCLUSIONS/SIGNIFICANCE: The spatio-temporal distribution of herbarium collections fits a simple biogeographical scenario for the emergence in cultivated rice fields followed by radiation in the wild of the CD genome in the Neotropics during the last four centuries. This probably occurred from species introduced to the Americas by humans and we found no evidence that the CD genome pre-existed in the Old World. We therefore propose a new evolutionary hypothesis for such a recent origin of the CD genome. Moreover, we exemplify how an historical approach can provide potentially important information and help to disentangle the timing of evolutionary events in the history of the Oryza genomes

Diversité et origines de la biodiversité à Madagascar : le message des fougères

International audienc

Clarifying the nomenclature of some Euro-Mediterranean quillworts (Isoetes, Isoetaceae): Indicator species and species of conservation concern

To stabilize the application of some names in the genus Isoetes in the Mediterranean biodiversity hotspot, we studied herbarium specimens and imaged spores with scanning electron microscopy, with special reference to those taxa in the I. longissima and I. histrix groups that were described from France, Algeria and Turkey, and are in need of a taxonomic revision. The following names are lectotypified: I. adspersa, I. boryana, I. delalandei, and I. viollaei. Holotypes of I. perralderiana and I. olympica were ascertained. We conclude that I. boryana (listed in the “Bern Convention” and in the European Union “Habitats” Directive) justifies consideration at species rank, but I. adspersa should be synonymized with I. longissima. Isoetes tenuissima and I. perralderiana are proposed as distinct species pending further studies. In the I. histrix group, we tentatively accept I. delalandei as a species, presenting some observations on “I. histrix f. subinermis” nom. nud. The latter might also represent a distinct species

Une fougère indigène nouvelle en danger critique d’extinction sur l’île Maurice : <i>Elaphoglossum coursii</i> Tardieu (Dryopteridaceae).

Dans les Mascareignes, Elaphoglossum coursii Tardieu (Dryopteridaceae) était connue uniquement à La Réunion. Cette espèce croît aussi à Madagascar, aux Comores et en Zambie. En novembre 2007, elle a été observée et récoltée pour la première fois sur l’île Maurice. En se fondant sur ces observations, nous discutons brièvement de l’écologie et du statut de conservation de cette espèce sur l’île Maurice.In the Mascarene Islands, Elaphoglossum coursii Tardieu (Dryopteridaceae) was only known in La Réunion. This species is also known to grow in Madagascar, the Comoro Islands and Zambia. In November 2007, this species was observed and collected for the first time in Mauritius. Based on these observations, a brief discussion is provided concerning the ecology and conservation status of this species in Mauritius

De nouvelles données moléculaires et morphologiques soutiennent une combinaison de <i>Blechnum bakeri</i> C.Chr. dans <i>Cranfillia</i> Gasper & V.A.O.Dittrich, élargissant ainsi la répartition de <i>Cranfillia</i> à Madagascar et à l’Afrique de l'Est

Au sein de la famille de fougères Blechnaceae, Cranfillia Gasper &amp; V.A.O.Dittrich et Austroblechnum Gasper &amp; V.A.O.Dittrich sont deux genres récemment décris à partir du fractionnement du genre Blechnum L. L’attribution des espèces au genre Cranfillia ou Austroblechnum peut être rendue difficile en raison de leurs similarités morphologiques. En nous focalisant sur Austroblechnum bakeri (C.Chr.) Gasper &amp; V.A.O.Dittrich, et en se basant sur de nouvelles données moléculaires et morphologiques, nous montrons que Austroblechnum bakeri appartient en fait au genre Cranfillia en tant que Cranfillia bakeri (C.Chr.) Vázquez Ferreira &amp; S. Molino, comb. nov. Cette nouvelle combinaison élargit la répartition du genre Cranfillia à Madagascar et à l’Afrique de l’Est. De plus, nous proposons que les paires de pennes basales partiellement adnées ainsi que les premières paires de pennes réfléchies pourraient représenter de nouveaux caractères diagnostiques discriminant Cranfillia de Austroblechnum. Enfin, nous apportons un traitement taxonomique de Cranfillia bakeri incluant tous les synonymes reconnus, et effectuons une lectotypification détaillée pour Blechnum bakeri C.Chr.In the fern family Blechnaceae, Cranfillia Gasper &amp; V.A.O.Dittrich and Austroblechnum Gasper &amp; V.A.O.Dittrich are two genera recently described from the splitting of Blechnum L. The assignation of species to Cranfillia or Austroblechnum could be difficult due to their morphological similarities. Focusing on Austroblechnum bakeri (C.Chr.) Gasper &amp; V.A.O.Dittrich, and based on new molecular and morphological evidence, we show that Austroblechnum bakeri actually belongs to the genus Cranfillia as Cranfillia bakeri (C.Chr.) Vázquez Ferreira &amp; S. Molino, comb. nov. This new combination extends the distribution of the genus Cranfillia to Madagascar and East Africa. Additionally, we propose that partially adnate basal pairs of pinnae and deflexed first pair of pinnae could represent new diagnostic characters to distinguish Cranfillia from Austroblechnum. Finally, we provide a taxonomic treatment of Cranfillia bakeri with all recognized synonyms, and conduct detailed lectotypification for Blechnum bakeri C.Chr.</p

Eastward colonization of the Mediterranean Basin by two geographically structured clades: The case of Odontites Ludw. (Orobanchaceae)

International audienceThe biogeography of Mediterranean groups is very heterogeneous, because of the complex geologic and climatic history of the region. Our goal was to reconstruct the spatio-temporal history of the genus Odontites. In particular, we aimed to infer its area of origin and colonization routes, investigate its timing of diversification, and examine possible correlations with major environmental events. Based on sequencing of three chloroplast markers (psbA–trnH, trnL–trnF and trnC–ycf6), we reconstructed phylogenetic relationships among species. We performed molecular dating analyses (based on a large-scale rbcL dataset), ancestral areas reconstructions, and interpreted the observed patterns in the light of the complex geologic and climatic histories of the region. Our results suggested that Bartsiella and Bornmuellerantha should be reintegrated into Odontites s.l. The genus originated in the Iberian Peninsula ca. 18.9 Ma and diverged into two main clades 16.2 Ma, but species diversification was most intense &lt;5–6 Ma. The two clades showed a clear geographic pattern: one clade originated in the Iberian Peninsula and Morocco, and extended its range to Eastern North Africa and the central Mediterranean Basin; the other clade originated in Europe and Western Asia, and mostly diversified within this ancestral area. The eastward colonization of the Mediterranean Basin contrasts with many other plant groups. Nevertheless, the burst of diversification in the Plio-Pleistocene agrees with what has been reported for other groups, and is concomitant with the end of the Messinian Salinity Crisis, onset of the Mediterranean climate and Quaternary glaciations. The link between phylogeny and geography suggests limited dispersal, and most dispersal events may have occurred overland rather than overseas