baconweed vs lamb's quarters

baconweed

noun
  • Synonym of pigweed (“the plant Chenopodium album”) 

lamb's quarters

noun
  • Chenopodium album, of the goosefoot family, sometimes used as a potherb 

  • Any of several similar plants of genera Chenopodium and Atriplex. 

How often have the words baconweed and lamb's quarters occurred in a corpus of books? (source: Google Ngram Viewer )