Frequency distribution of intraspecific distances (blue) and interspecific distances (orange). A gap between intra- and interspecific distances illustrates the barcode gap in the genus.  
  Part of: Marthinsen G, Rui S, Timdal E (2019) OLICH: A reference library of DNA barcodes for Nordic lichens. Biodiversity Data Journal 7: e36252. https://doi.org/10.3897/BDJ.7.e36252