boxthorn vs coralberry

boxthorn

noun
  • Any plant of the genus Lycium. 

coralberry

noun
  • American winterberry, Ilex verticillata. 

  • Symphoricarpos orbiculatus, of eastern North America. 

  • Ardisia crenata of east Asia. 

  • A species of bromeliad, Aechmea fulgens, of Brazil, and which is often used as an ornamental plant. 

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