bifurcate vs unbranched

bifurcate

verb
  • To cause to bifurcate. 

  • To divide or fork into two channels or branches. 

adj
  • Divided or forked into two; bifurcated. 

  • Having bifurcations. 

unbranched

adj
  • straight-chain 

  • Having no branches 

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