retroserrate vs runcinate

retroserrate

adj
  • Having tooth-like projections pointed away from the apex. 

runcinate

adj
  • Having tooth-like projections pointing away from the apex. 

  • Having a lacerated aspect with the projection pointing away from the apex, like dandelion leaves. 

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