foliage vs frond

foliage

noun
  • The leaves of plants. 

  • Fall foliage. 

  • An architectural ornament representing foliage. 

frond

noun
  • The leaf of a fern, especially a compound leaf. 

  • Any fern-like leaf or other object resembling a fern leaf. 

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