knotgrass vs wild asparagus

knotgrass

noun
  • Paspalum distichum, a weedy perennial grass of wet areas 

  • An annual plant, Polygonum aviculare, found in fields and wasteland 

wild asparagus

noun
  • Asparagus acutifolius, a species of asparagus common in the Mediterranean basin. 

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