endocarp vs rhizome

endocarp

noun
  • The woody inner layer of the pericarp of some fruits that contains the seed. 

rhizome

noun
  • A horizontal, underground stem of some plants that sends out roots and shoots (scions) from its nodes. 

  • A so-called “image of thought” that apprehends multiplicities. 

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