01530nas a2200157 4500008004100000022001400041245007600055210007000131300001200201490000800213520103300221100002101254700001501275700001901290856006301309 2003 eng d a0378-269700aFlower size dimorphism in diclinous plants native to La Réunion Island0 aFlower size dimorphism in diclinous plants native to La Réunion  a163-1730 v2403 a

Although many diclinous plants have a flower size dimorphism, the causes and ecological correlates of dimorphism in flower size remain poorly understood. In this paper we quantify the frequency and distribution of flower size dimorphism in the native flora of La Réunion Island. The frequency of flower size dimorphism is lower than in a previous global study suggesting that the dimorphism may limit colonisation success. Flower size dimorphism is significantly more frequent in endemic taxa compared to indigenous taxa, a trend that is particularly evident at the species level, due to the large number of species with male flowers bigger than female flowers and is more common in species-rich lineages. These results suggest that flower size dimorphism may be associated with species divergence. The direction of dimorphism varies between dioecious and monoecious species, suggesting that the mechanisms acting on flower size variation differ in species with these different sexual systems.

1 aHumeau, Laurence1 aPailler, T1 aThompson, J, D uhttp://link.springer.com/article/10.1007/s00606-003-0011-402058nas a2200241 4500008004100000245008600041210006900127300001200196490000700208520132000215653000901535653001001544653001101554653001301565653003001578653001401608100002601622700002201648700002101670700002101691700001901712856008501731 2013 eng d00aVertebrate pollination of the endemic Trochetia granulata (Malvaceae) on Réunion0 aVertebrate pollination of the endemic Trochetia granulata Malvac a353-3560 v293 a

The pollination ecology and breeding system of Trochetia granulata (Malvaceae), an endemic tree species from Réunion were studied. In 2010–2011, compatibility studies were conducted on a total of 154 flowers from 35 different individuals using three different hand pollination treatments: (a) autofertility, (b) self-pollination and (c) cross-pollination. During the period, we also studied the pollination ecology of T. granulata. During 48 h of video recordings, we tracked flower visits to T. granulata in six different sites and studied the behaviour of the visitors. The results from the hand-cross experiments show that T. granulata is self-compatible (60.8% fruit set) but cannot produce fruit (5.4% fruit set) without the visit of a pollen vector. During surveys, four different visitors were reported: the introduced honey bee (Apis mellifera), two endemic species of white-eye (Zosterops borbonicus borbonicus and Z. olivaceus) and the endemic Réunion day gecko (Phelsuma borbonica). This study documented a new case of vertebrate-pollination by lizard and birds in an insular context. These interactions might be linked to several uncommon floral traits of Trochetia species.

10aApis10agecko10aisland10aPhelsuma10aplant-animal interactions10aZosterops1 aLe Péchon, Timothée1 aSanchez, Mickaël1 aHumeau, Laurence1 aGigord, Luc, D B1 aZhang, Li-Bing uhttp://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=894869800457nas a2200133 4500008004100000245009200041210006900133300001000202490000800212100002100220700001500241700001900256856004800275 1999 eng d00aVariation in the breeding system of two sympatric Dombeya species on La Réunion island0 aVariation in the breeding system of two sympatric Dombeya specie a77-870 v2181 aHumeau, Laurence1 aPailler, T1 aThompson, J, D uhttps://dombeya.myspecies.info/fr/node/129500467nas a2200133 4500008004100000245009700041210006900138300001400207490000700221100002100228700001500249700001900264856005000283 1999 eng d00aCryptic dioecy and leaky dioecy in endemic species of Dombeya (Sterculiaceae) on La Réunion0 aCryptic dioecy and leaky dioecy in endemic species of Dombeya St a1437-14470 v861 aHumeau, Laurence1 aPailler, T1 aThompson, J, D uhttp://www.amjbot.org/content/86/10/1437.long00719nam a2200205 4500008004100000245009400041210006900135260004400204100002600248700002100274700002100295700002500316700001300341700002000354700001400374700001500388700001400403700001700417856007900434 2011 eng d00aLes Mahots des Mascareignes : base de connaissances sur les Dombeyoideae des Mascareignes0 aLes Mahots des Mascareignes base de connaissances sur les Dombey aSaint-DenisbUniversité de La Réunion1 aLe Péchon, Timothée1 aHumeau, Laurence1 aGigord, Luc, D B1 aPausé, Jean-Bernard1 aCaron, D1 aBaider, Claudia1 aGigord, P1 aGrosser, D1 aHansen, D1 aSevathian, J uhttp://mahots.univ-reunion.fr/sortie-du-livre-les-mahots-des-mascareignes/03028nas a2200229 4500008004100000245015200041210007100193260004400264490000800308520224900316653002302565653001302588653001202601653001602613653002102629653001602650653001802666653001802684653002202702100002102724856005302745 1999 eng d00aEcologie et évolution de la dioécie et du dimorphisme sexuel de la taille des fleurs chez les Dombeya (Sterculiacées) endémiques de la Réunion0 aEcologie et évolution de la dioécie et du dimorphisme sexuel de  aSaint-DenisbUniversité de La Réunion0 vPhD3 a

Les forts taux d'espèces dioïques sur les îles ont longtemps fasciné les biologistes. Or le fonctionnement de la dioécie en milieu insulaire a été peu abordé. Les variations dans l'expression de la dioécie et du dimorphisme sexuel de la taille des fleurs sont aujourd'hui examinés dans l'archipel des Mascareignes. A la réunion, les espèces unisexuées du genre "Dombeya" (sterculiacées) sont dioïques cryptiques mais présentent une variabilité dans l'expression de la dioécie. Certaines espèces strictement dioïques constituent de grandes populations en altitude alors que les espèces partiellement dioïques forment de petites populations à basse altitude. Par ailleurs, l'hybridation entre espèces strictement dioïques et partiellement dioïques semble engendrer des taxons hermaphrodites autocompatibles. Ces résultats demandent confirmation par une étude moléculaire plus poussée, mais l'hybridation en milieu insulaire semble être un processus évolutif important dans ce genre. Nos résultats montrent que le dimorphisme sexuel de la taille des fleurs de la flore unisexuée indigène de la Réunion est un phénomène largement répandu. Le biais observé est souvent en faveur des individus mâles, ce qui peut être corrélé à la zoogamie, fréquente sur cette île. Le dimorphisme est plus abondant chez les espèces endémiques que chez les taxons indigènes et est variable entre les espèces apparentées. Un modèle allométrique est proposé pour illustrer ces variations au sein du genre "Dombeya". Cette thèse apporte les connaissances de base sur la biologie du genre "Dombeya" à la Réunion dont certaines espèces constituent les éléments clés des forêts primaires et d'autres sont des espèces rares des milieux fragmentés.

10aDimorphisme sexuel10adioécie10aDombeya10ahybridation10aIles océaniques10aLa Réunion10aOcéan Indien10aSterculiaceae10aTaille des fleurs1 aHumeau, Laurence uhttp://tel.archives-ouvertes.fr/tel-00488723/en/02337nas a2200277 4500008004100000020001400041022001400055245013600069210007000205300001200275490000700287520147100294653001101765653001601776653001701792653001401809653001301823100002601836700002501862700002501887700002101912700002301933700002301956700002101979856005902000 2013 eng d a1548-2324 a0363-644500aDombeya formosa (Malvaceae s.l.): A New Species Endemic to La Réunion (Indian Ocean) Based on Morphological and Molecular Evidence0 aDombeya formosa Malvaceae sl A New Species Endemic to La Réunion a424-4330 v383 a

Dombeya formosa (Malvaceae s.l. or Dombeyaceae), a new species endemic to La Réunion, is described and illustrated. The species is distinguishable by its ovate leaves with round or slightly cordate bases, round to lightly acute apices and glabrescent abaxial surfaces, subulate and persistent stipules, umbellate inflorescences, and acute apices of floral bracts. Dombeya formosa is morphologically close to Dombeya punctata Cav. but differs from it in having ovate leaves and acute apices on floral bracts. Dombeya formosa is also morphologically similar to D. ficulnea Baill. but can be distinguished from it by its persistent and subulate stipules as well as the glabrescent adaxial surface of its leaves. Our study, focusing on 16 quantitative floral characters, demonstrates that there is a clear morphological distinction between D. formosa, D. punctata, and D. ficulnea. In comparison to the other two species, Dombeya formosa possesses smaller flowers and additionally shows cryptic dioecy along with flower-size dimorphism between sexes. Amongst the Mascarene Dombeyoideae, it is the only species distributed up to an altitude of 2,100 m. The phylogenetic position of Dombeya formosa is consistent with the morphological features and locates the species within the clade endemic to La Réunion characterized by umbellate inflorescences.

10aDioecy10aDombeyaceae10aDombeyoideae10aPhylogeny10ataxonomy1 aLe Péchon, Timothée1 aPausé, Jean-Bernard1 aDubuisson, Jean-Yves1 aGigord, Luc, D B1 aHaevermans, Agathe1 aHaevermans, Thomas1 aHumeau, Laurence uhttp://www.bioone.org/doi/abs/10.1600/036364413X666732