Rhubarb

Rhubarb (Rheum rhabarbarum) is a species of plant in the family Polygonaceae. It is a herbaceous perennial growing from short, thick rhizomes. The fleshy, edible leaf stalks (petioles) are used in cooking, but the large, triangular leaves contain high levels of oxalic acid, making them inedible. The small flowers are grouped in large compound leafy greenish-white to rose-red inflorescences.

Question: can you eat the leaves of a rhubarb plant
Answer: no