bellwort vs harebell

bellwort

noun
  • Any of various plants in the Campanulaceae family. 

  • Any of several perennial plants, of the genus Uvularia, that have yellow, bell-shaped flowers. 

harebell

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

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