frutex vs thornbush

frutex

noun
  • A plant with a woody, durable stem, but less than a tree; a shrub. 

thornbush

noun
  • Any of many thorny or spiny shrubs and bushes. 

  • Hyponyms: bramble, briar 

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