aroid vs calla

aroid

noun
  • Any plant of the family Araceae, found chiefly in the tropics. 

calla

noun
  • The calla lily, Zantedeschia aethiopica. 

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

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