For the term pertaining to baseball, see bench-clearing brawl. Rhubarb (Rheum rhabarbarum) is a species of plant in the family Polygonaceae. It is a herbaceous perennial growing from short, thick rhizomes. It produces large poisonous leaves that are somewhat triangular, with long fleshy edible stalks and small flowers grouped in large compound leafy greenish-white to rose-red inflorescences. In culinary use, fresh raw leaf stalks (petioles) are crisp (similar to celery, although they do not share the same family) with a strong, tart taste. Although rhubarb is not a true fruit, in the kitchen it...