Orobanche lycoctoni Rhiner, a neglected broomrape species of the Central European flora

Orobanche lycoctoni Rhiner is a poorly known species described from eastern Switzerland, which is not closely related to O. flava Mart. ex F.W. Schultz, as previously thought, but instead constitutes a separate lineage with unclear relationships to other broomrapes. Here, we report on its occurrence in the Julian Alps (Slovenia), thus significantly extending its known distribution area (Cantabrian mountains and Glarner Alps). We provide a detailed phytocoenological characterization of this species inferred from these newly found localities. This species differs from O. flava mainly by its yellow-whitish colour, corolla curvature, glabrous corolla lobes, rather disc-like (instead of bilobed) stigma, and the host plant Aconitum lycoctonum L.