Zantedeschia aethiopica vs calla lily

Zantedeschia aethiopica

calla lily

noun
  • A common name for certain flowering plants in the genus Zantedeschia; not related to either the genus Calla or the true lilies (Liliaceae) 

  • A flower of one of these plants. 

How often have the words Zantedeschia aethiopica and calla lily occurred in a corpus of books? (source: Google Ngram Viewer )