heliotrope vs stigma

heliotrope

noun
  • The fragrance of heliotrope flowers. 

  • A light purple or violet colour. 

  • Particularly, a purple-flowered plant of the species Heliotropium arborescens. 

  • A bloodstone (a variety of quartz). 

  • An instrument, employed in triangulation, that uses a mirror to reflect sunlight toward another, very distant, surveyor. 

  • A plant that turns so that it faces the sun. 

adj
  • Light purple or violet. 

  • Keeping one’s face turned toward the sun. 

stigma

noun
  • The sticky part of a flower that receives pollen during pollination. 

  • A mark on the body corresponding to one of the wounds of the Crucifixion on Jesus' body, and sometimes reported to bleed periodically. 

  • A mark of infamy or disgrace. 

  • A scar or birthmark. 

  • A visible sign or characteristic of a disease. 

  • An outward sign; an indication. 

  • A ligature of the Greek letters sigma and tau, (Ϛ/ϛ). 

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