Plastid sequence divergence is broadly consistent with prior, morphologically circumscribed taxa and indicates a division between H. hircinum-adriaticum to the west of the Carpathians and H. jankae-caprinum (plus local endemics) to the east, a distinction also suggested by nrITS ribotypes. LEAFY phylogenies are less congruent with prior taxonomic arrangements and include one likely example of paralogy. Himantoglossum metlesicsianum fully merits its IUCN Endangered status. Potentially significant genetic variation was detected within Steveniella satyrioides, H. robertianum and H. hircinum. However, confident circumscription of the more derived species of Himantoglossum s.s., including local endemics of hybrid origin, must await future morphometric and population-genetic analyses.

Although hybridization has long been recognized as a major force driving speciation in land plants, it has not yet been evidenced in Astragalus, the largest angiosperm genus. Here, we reveal the possible contribution of hybridization to speciation in Astragalus by employing cloning of the nrDNA ITS region and sampling three plastid regions (ycf1, ndhF-rpl32, and rpl32-trnL) in taxa belonging to sect. Dissitiflori. Phylogenetic network and tree analyses uncovered various levels of intra-individual and intraspecific polymorphism of ITS in most of the taxa investigated. Two distantly related ribotype groups were found to be shared by the closely related polyploids Astragalus pallescens M.Bieb., Astragalus peterfii Jáv., and Astragalus pseudoglaucus Klokov suggesting ancient hybridization followed by incomplete lineage sorting (i.e., shared ancestral polymorphism) in nrDNA ITS. Reticulation is also invoked as an underlying evolutionary process behind the statistically highly supported incongruent placement of A. pseudoglaucus and Astragalus vesicarius subsp. pastellianus (Pollini) Arcang. in nuclear versus plastid phylogenies. The phylogenetic results also shed light on taxonomic controversies in the section, such as the false synonimization of A. peterfii under A. vesicarius s.l. Our results provide evidence for the (at least past) existence of speciation processes driven by hybridization in Astragalus.Key words: hybridization, ycf1, nrDNA ITS cloning, allopolyploidy, reticulation.Résumé : Bien qu'on ait reconnu depuis longtemps l'hybridation comme force majeure soutenant la spéciation chez les plantes terrestres, on n'en pas encore la preuve chez les Astragalus spp, le plus important genre des angiospermes. On évoque ici la contribution possible de l'hybridation à la spéciation des Astragalus spp., en utilisant le clonage de la région ITS du nrADN et en échantillonnant trois régions plastidiques (ycf1, ndhF-rpl32 et rpl32-trnL) chez des taxons de la section Dissitiflori. Le réseau phylogénétique et trois analyses révèlent divers degrés de polymorphisme intra-individuel et intraspecifique de l'ITS, chez la plupart des taxons examinés. On a repéré deux groupes de ribotypes partagés par l'Astragalus pallescens M. Bieb., l'Astragalus peterfii Jáv., et l'Astragalus pseudoglaucus Klokov, des polyploïdes étroitement reliées, ce qui suggère d'anciennes hybridations suivies de sélections de lignées incomplètes (i. e. polymorphisme ancestral partagé) dans l'ITS nrADN. On évoque la réticulation comme processus évolutif sous-jacent, également à la source de la localisation incongrue, fortement supportée statistiquement, de l'A. pseudoglaucus et de l'Astragalus vesicarius subsp. pastellianus (Pollini) Arcang. dans les phylogénies nucléiques versus plastidiques. Les résultats phylogénétiques éclairent les controverses sur la section, tel la fausse synonymie de l'A. peterfii sous l'A. vesicarius s.l. Les résultats fournissent la preuve (du moins dans le passé) de l'existence de processus de spéciation activés par l'...