leaf node vs offshoot

leaf node

noun
  • One of the spots upon a stem where buds and intercalary meristems occur, usually marking the end of a season's growth. 

  • A node, in a tree, that has no children. 

offshoot

noun
  • That which shoots off or separates from a main stem or branch of a plant. 

  • That which develops from something else. 

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