horseweed vs witloof

horseweed

noun
  • A plant of the species Cichorium intybus 

  • Any of various flowering plants of the genus Conyza. 

witloof

noun
  • Belgian endive, common chicory (Cichorium intybus) 

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