black jack vs shepherd's needle

black jack

noun
  • Bidens spp., from the family of Asteraceae 

  • Sphalerite. 

  • Caranx lugubris, a gamefish 

shepherd's needle

noun
  • Beggarticks (Bidens spp.) 

  • Venus' comb (Scandix pecten-veneris) 

How often have the words black jack and shepherd's needle occurred in a corpus of books? (source: Google Ngram Viewer )