Mesembryanthemum crystallinum vs icicle plant

Mesembryanthemum crystallinum

icicle plant

noun
  • A plant in the daisy family,Asteraceae, with long, powdery-white leaves (Helichrysum thianschanicum). 

How often have the words Mesembryanthemum crystallinum and icicle plant occurred in a corpus of books? (source: Google Ngram Viewer )