dry rot vs toadstool

dry rot

noun
  • A fungal infection which affects plants, in particular potatoes. 

  • The crumbly, friable decayed portions of wooden members of buildings, especially at or below grade, usually caused by a fungal infection. 

  • Any progression of decay, corruption, or obsolescence. 

toadstool

noun
  • Any inedible or poisonous mushroom, especially an agaric. 

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