noun, plural: petioles
(1) (botany) The stalk at the base of the leaf blade, attaching and supporting the leaf blade to the stem.
(2) (entomology) The slender stalk connecting the mesosoma and the gaster of ants.
(3) (entomology) The stalk of the nest of the paper wasps, attaching the nest to the substrate protecting the brood from other insects (e.g. ants) through a chemical secreted by the wasps.
(Botany) Flowering plants may be classified based on their petioles:
(Entomology) The petioles in ants are used for their identification. Some ants have single segment while others have two segments. The two segments are referred to by others as (1) the petiole and (2) the post-petiole). The structure connecting the mesosoma and the gaster of ants serves as the "waist" of the ant.
(Entomology) Paper wasps secrete a chemical around the petiole of their nest to repel other insects (such as ants) thereby protecting the young from these insects.
Word origin: from Latin petiolus (little foot), from pēs (foot)