Jerusalem cross vs dusky salmon

Jerusalem cross

noun
  • a cross variant consisting of a large cross potent surrounded by four smaller Greek crosses, one in each quadrant. 

  • A flowering plant Lychnis chalcedonica (syn. Silene chalcedonica) of the family Caryophyllaceae 

dusky salmon

How often have the words Jerusalem cross and dusky salmon occurred in a corpus of books? (source: Google Ngram Viewer )