black haw vs stag bush

black haw

noun

  • Viburnum prunifolium. 

  • Sideroxylon lanuginosum, also native to Mexico. 

  • Viburnum rufidulum (rusty blackhaw). 

  • Viburnum lentago. 

stag bush

How often have the words black haw and stag bush occurred in a corpus of books? (source: Google Ngram Viewer )