mayflower vs pinna

mayflower

noun
  • Any of several plants that flower in May - especially the hawthorn (in Britain) and the trailing arbutus (in the US). 

pinna

noun
  • A leaflet or primary segment of a pinnate compound leaf. 

  • The visible part of the ear that resides outside of the head, the auricle; outer ear excluding the ear canal. 

  • A feather, wing, fin, or other similar appendage. 

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