apple tree vs malus

apple tree

noun
  • Any tree that bears apples, principally Malus domestica but also certain wild species. 

malus

noun
  • A plant of the genus Malus (the apples). 

  • The loss or return of performance-related compensation originally paid by an employer to an employee as a result of the discovery of a defect in the performance. 

  • A penalty or negative thing. 

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