amyloplast

amyloplast (ăm`əlōplăst'), also called leucoplast, a nonpigmented organelle, or plastid, occurring in the cytoplasm of plant cells. Amyloplasts transform glucose, a simple sugar, into starch through the process of polymerization, and store starch grains within their stretched membranes. Especially large numbers occur in subterranean storage tissues of some plants, such as the common potato.