Zantedeschia aethiopica vs calla

Zantedeschia aethiopica

calla

noun
  • A marsh plant native to cooler areas throughout the northern hemisphere, Calla palustris, having pale green flowers in a white spathe. 

  • The calla lily, Zantedeschia aethiopica. 

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