artemisia vs southernwood

artemisia

noun
  • Any of many aromatic flowering plants of the genus Artemisia, including wormwood, sagebrush, and tarragon, often used as traditional medicine and flavouring. 

southernwood

noun
  • An aromatic shrub, Artemisia abrotanum, related to wormwood. 

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