Nigritella widderi (Orchidaceae) from central Apennines (Italy): evidence of plastome differentiation events
The present study focuses on the taxonomic and systematic classification of the tetraploid species Nigritella widderi, a rare orchid distributed in the eastern Alps (i.e., Austria, Germany, Italy, Slovenia) and in central Apennines (Italy). The research was fueled by the hypothesis that geographic isolation—or alternat...