annulate vs orbiculate

annulate

adj
  • Having an annular form or shape. 

  • Describes a mushroom with an annulus on the stipe. 

  • Describes a fern sporangium that has an annulus. 

noun
  • One of the Annulata. 

orbiculate

adj
  • spherical or circular; orbicular 

noun
  • That which is orbiculate, especially a solid whose vertical section is oval and whose horizontal section is circular. 

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