haulm vs petiole

haulm

noun
  • An individual plant stem. 

  • The stems of various cultivated plants, left after harvesting the crop, which are used as animal food or litter, or for thatching. 

  • Part of a harness; a hame. 

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 haulm and petiole occurred in a corpus of books? (source: Google Ngram Viewer )