black caraway vs fennel flower

black caraway

noun
  • A Middle-Eastern spice plant related to buttercups, Nigella sativa, with dark black, aromatic seeds. 

  • A spice plant related to caraway and cumin, with dark seeds and an edible root, Bunium bulbocastanum 

  • These seeds as spice. 

fennel flower

How often have the words black caraway and fennel flower occurred in a corpus of books? (source: Google Ngram Viewer )