stirps vs taxon

stirps

noun
  • A superfamily of animals or plants. 

  • A branch of a family. 

  • A progenitor of a branch of a family. 

taxon

noun
  • A group of one or more populations of an organism or organisms seen by taxonomists to form a unit. 

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