Sampling sites in the Retezat Mountains. (a) Map showing the location of the Retezat Mountains in Europe and (b) in the Carpathians; H: herbarium sample; AF: Austrian Alps. (c) Relief map of the Retezat Mts showing the position of Tăul dintre Brazi lake with location of the extant samples analysed in this study. The location of herbarium specimens is shown in map (b). On map (c) labels mark valleys and tracks in the Retezat Mountains; CP: Carnic-Pietrele; St: Valea Stanisoarei; P: Valea Pietrele; R: Vale Rea; Gt(k): Valea Gales; Buk: Valea Bucura; KR: Rtezatul Mic; B: Buta; M. Valea Marii; Z: Vale Zanoaga.