capsicum vs green pepper

capsicum

noun
  • The spicy fruit of the above plants, the bell pepper. 

  • Any of several tropical American plants, of the genus Capsicum, principally the species Capsicum annuum and Capsicum frutescens, that are cultivated as edible peppers. 

green pepper

noun
  • The green, unripe, form of the sweet bell pepper. Popular in cooking, especially Italian cuisine. The unripe bell pepper is green and generally changes to other colors as it matures, cultivars exist for red, orange, yellow and other shades. 

  • A green variety of dried peppercorn, made from the unripe berries by treating them in a manner that retains the green colour. 

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