Its common name comes from its shiny, dark leafstalks that resemble human hair. Rhubarb is grown primarily for its fleshy leafstalks, technically known as petioles. Upper cauline leaves are smaller, lanceolate with pointy ends, shorter leafstalks, and spiny margin. The seeds are edible, as are the young leafstalks after being cooked. The leaves, leafstalks, roots and flower stalks are all edible when prepared correctly. The young stems and leafstalks were peeled and usually eaten raw.