aril vs glume

aril

noun
  • A tissue surrounding the seed in certain fruits such as pomegranates. 

glume

noun
  • A basal, membranous, outer sterile husk or bract in the flowers of grasses (Poaceae) and sedges (Cyperaceae). 

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