famine weed vs oxtongue

famine weed

noun
  • A plant of the species Parthenium hysterophorus, native to Central America, considered invasive in Africa, India, Australia 

oxtongue

noun
  • A flowering plant of the genus Anchusa, especially Anchusa officinalis (true alkanet). 

  • Beef tongue (a foodstuff). 

  • A flowering plant of the genus Picris, especially Picris echioides (bristly oxtongue). 

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