aroid vs arum lily

aroid

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

arum lily

noun
  • Any of several flowering plants, of the family Araceae, but especially Zantedeschia aethiopica, the calla lily that has a showy white spathe. 

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