x Pseudorhiza nieschalkii (Senghas) P.F.Hunt nothosubsp. siculorumH.Kertesz & N.Anghelescu, 2020AN INTERGENERIC ORCHID HYBRID NEW TO SCIENCE FOUND IN TERRA SICULORUM, ROMANIA

Abstract

We describe the first reported intergeneric hybrid to naturally occur between two subspecies belonging to different genera, Dactylorhiza fuchsii subsp. sooana (genus Dactylorhiza) and Pseudorchis albida subsp. tricuspis (genus Pseudorchis), as x Pseudorhiza nieschalkii (Senghas) P.F.Hunt nothosubsp. siculorum H.Kertesz & N.Anghelescu, 2020. The hybrid was found and digitally photographed for the first time by Hajnalka Kertesz in June, 2020, within Terra Siculorum, in one of the Natura 2000 protected areas, known as Harghita M[a]d[a]ras, ROSCI00090. Following detailed morphometric analysis using 67 characters and molecular karyological analyses, we identified this unique specimen as an intergeneric hybrid, new to science. The hybrid, an F1 generation plant, most likely representing a single intergeneric pollination event, is phenotypically intermediate between its parental species in most of the characters scored, but it significantly closely resembles Pseudorchis albida subsp. tricuspis parent. Since the parental species occurred in near proximity (1-10 meters distance), we suggest that the production of this hybrid required a minimum travel distance of ca 1-10 meters, by the pollinators and frequent exchange of pollen between the parental species was very likely. The parental species and the hybrid, which display a considerable synchronicity in their flowering time, overlap in pollinator community, sharing various species of Hymenopterans and Dipterans, very abundant in the heathland. This Terra Siculorum hybrid is thus best described as a rarely occurring intergeneric hybrid that shows strong Pseudorchis albida subsp. tricuspis parental dominance in inheritance patterns.