glaucous vs virescent

glaucous

adj
  • Of a pale grey or bluish-green, especially when covered with a powdery residue. 

  • Covered with a bloom or a pale powdery covering, regardless of colour. 

virescent

adj
  • Green-like, greenish. 

  • Becoming green. 

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