bract vs petiole

bract

noun
  • A leaf or leaf-like structure from the axil out of which a stalk of a flower or an inflorescence arises. 

petiole

noun
  • The stalk of a leaf, attaching the blade to the stem. 

  • A narrow or constricted segment of the body of an insect; especially, the metasomal segment of certain Hymenoptera, such as wasps. 

  • The stalk at the base of the nest of the paper wasp. 

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