common yarrow vs thousand-leaf

common yarrow

noun
  • Achillea millefolium, a flowering plant widespread in the temperate Northern Hemisphere, formerly and sometimes used to stanch the flow of blood. 

thousand-leaf

noun
  • Achillea millefolium or common yarrow, a flowering plant widespread in the temperate Northern Hemisphere, featuring finely divided leaves. 

How often have the words common yarrow and thousand-leaf occurred in a corpus of books? (source: Google Ngram Viewer )