cherry pie vs common heliotrope

cherry pie

noun
  • Heliotropium arborescens. 

  • Any of various willowherbs 

  • A pie baked with a cherry filling. 

common heliotrope

noun
  • A summer-growing annual native flower of Southern and Central Europe, Western Asia and Northern Africa (Heliotropium europaeum). 

How often have the words cherry pie and common heliotrope occurred in a corpus of books? (source: Google Ngram Viewer )