mugwort vs wormwood

mugwort

noun
  • Artemisia vulgaris, traditionally used medicinally. 

  • Any of several aromatic plants of the genus Artemisia native to Europe and Asia. 

wormwood

noun
  • An intensely bitter herb (Artemisia absinthium and similar plants in genus Artemisia) used in medicine, in the production of absinthe and vermouth, and as a tonic. 

  • Something that causes bitterness or affliction; a cause of mortification or vexation. 

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