red nightshade vs yellow nightshade

red nightshade

noun

  • Solanum villosum 

  • Phytolacca americana syn. Phytolacca decandra 

yellow nightshade

noun

  • Solanum villosum 

  • Physalis crassifolia 

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