citrus vs clementine

citrus

noun
  • The fruit of such plants, generally spherical, oblate, or prolate, consisting of an outer glandular skin (called zest), an inner white skin (called pith or albedo), and generally between 8 and 16 sectors filled with pulp consisting of cells with one end attached to the inner skin. Citrus fruits include orange, grapefruit, lemon, lime, and citron. 

  • Any of several shrubs or trees of the genus Citrus in the family Rutaceae. 

adj
  • Of, relating to, or similar to citrus plants or fruit. 

clementine

noun
  • A type of small, sweet orange, the result of a cross between a tangerine and Seville orange. 

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