Euphrasia ultima, a new locally endemic diploid species from the Ortler/Ortles range (Italy), is a close relative of widespread allotetraploid E. minima.

The goal of this study was to tackle two questions related to the systematics of small-flowering Euphrasia species from the Eastern Alps. Our first aim was to test the hypothesis of a wider distribution of diploid E. inopinata, considered endemic to the uppermost Ötztal valley in Austria based on ploidy screening of ca. 70 populations along a latitudinal transect. We failed to find new populations of E. inopinata but during the sampling campaign, a diploid population was detected in the eastern Ortler/Ortles mountain range (Italy), which could neither be assigned to E. inopinata nor to E. minima. Thus, our second aim was to clarify, based on a comprehensive sampling of individuals and the use of Amplified Fragment Length Polymorphisms (AFLPs) and/or morphometric data, if this diploid population is morphologically and genetically consistently divergent from both, tetraploid widespread E. minima and E. inopinata. As this was confirmed, we established the relationships of the new entity based on Internal Transcribed Spacer sequences, which uncovered a close relationship with E. minima and describe it here as a new diploid species, E. ultima, which, based on current knowledge, is locally endemic even if a bigger distribution area appears likely. [ABSTRACT FROM AUTHOR]