neem vs syringa

neem

noun
  • Azadirachta indica, a large, mostly evergreen tree from India, whose seeds yield the insecticide azadirachtin. 

syringa

noun
  • Any of several flowering plants, of the genus Syringa, such as the lilacs. 

  • Hence any of several flowering plants of the genus Philadelphus, such as now in the Western United States Philadelphus lewisii. 

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