drupe vs seedling

drupe

noun
  • a kind of fruit, with a fleshy exterior, formed from the exocarp and mesocarp, surrounding a hardened endocarp which protects the seed. 

seedling

noun
  • A young plant grown from seed. 

  • a tree smaller than a sapling. 

  • one grown in a nursery for transplanting. 

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