green nightshade vs red nightshade

green nightshade

noun

  • Solanum physalifolium 

  • Solanum sarrachoides 

red nightshade

noun

  • Solanum villosum 

  • Phytolacca americana syn. Phytolacca decandra 

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