 In plants such as rhubarb ("Rheum rhabarbarum"), celery ("Apium graveolens"), artichokes and cardoons ("Cynara cardunculus") the petioles ("stalks" or "ribs") are cultivated as edible crops.The petiole of rhubarb grows directly from the rhizome and produces the leaf at its end.Botanically it is categorized as a vegetable and culinarily used as a fruit.