Hottentot fig vs ice plant

Hottentot fig

noun
  • Carpobrotus edulis, a South African plant. 

  • The acidic edible fruit of this plant. 

ice plant

noun
  • Especially, Carpobrotus edulis. 

  • A succulent annual, Mesembryanthemum crystallinum, of the fig marigold family, having pale pink flowers and fleshy leaves covered with glistening water vesicles. 

  • Any of several plants in fig marigold family, Aizoaceae, which were formerly classified in the genus Mesembryanthemum along with Mesembryanthemum crystallinum. 

How often have the words Hottentot fig and ice plant occurred in a corpus of books? (source: Google Ngram Viewer )