Long pinkish sour leafstalks usually eaten cooked and sweetened WordNet 3.0 & Open English WordNet

A plant (Rheum rhaponticum) whose acid leafstalks are used in making pies; the garden rhubarb. Wiktionary

The leafstalks of common rhubarb or garden rhubarb (usually known as Rheum × hybridum), which are long, fleshy, often pale red, and with a tart taste, used as a food ingredient; they are frequently stewed with sugar and made into jam or used in crumbles, pies, etc. Wiktionary