milkweed vs spurge

milkweed

noun
  • Euphorbia peplus and Euphorbia heterophylla, in order Malpighiales. 

  • Principally of the genus Asclepias in order Gentianales, family Apocynaceae 

  • A monarch butterfly (Danaus spp). 

  • Also of the genus Calotropis in order Gentianales, family Apocynaceae 

spurge

noun
  • Any plant of the genus Euphorbia, a diverse genus of over 2,000 species. 

verb
  • To emit foam; to froth; said of the emission of yeast from beer during fermentation. 

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