floret vs plumule

floret

noun
  • A small flower, especially one of a cluster in a composite flower. 

plumule

noun
  • The first bud, or growing point, of a plant embryo, situated above the cotyledons. 

  • One of the featherlike scales of certain male butterflies. 

  • The aftershaft of a feather. 

  • A down feather. 

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