gemma vs papilla

gemma

noun
  • An asexual reproductive structure, as found in animals such as hydra (genus Hydra) and plants such as liverworts (division Marchantiophyta), consisting of a cluster of cells from which new individuals can develop; a bud. 

papilla

noun
  • A vascular process of connective tissue extending into and nourishing the root of a hair, feather, or developing tooth. 

  • Any of the small protuberances on the upper surface of the tongue often containing taste buds. 

  • A small fleshy projection on a plant. 

  • Any of the vascular protuberances of the dermal layer of the skin extending into the epidermal layer and often containing tactile corpuscles. 

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