common chicory vs harebell

common chicory

noun
  • Cichorium intybus, a somewhat woody perennial herbaceous plant of the dandelion family, many varieties of which are cultivated for salad leaves. 

harebell

noun
  • A perennial flowering plant, Campanula rotundifolia, native to the Northern Hemisphere, with blue, bell-like flowers. 

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