Bunchstem

bunchstem, the stem of a grapevine inflorescence, or bunch of grapes, known by botanists as the peduncle and in French as a rafle. The form of the bunchstem, especially the position and length of lateral branches, determines the shape of the bunch and is one of many characters used to identify vine varieties in the science of ampelography. Winemakers often refer to bunchstems as stems or stalks (see destemming, for instance).