Potato starch grains Light micrograph of a transverse section through a potato tuber Solanum tuberosum showing the starch grains A pale central cross called the hilum marks the highest point of a starch grain Starch is made from sucrose a sugar formed in the leaves during photosynthesis which is then transported to the tuber potato by the phloem vascular tissue It is used as a store of energy for the later development of buds on the surface of the potato Magnification x when printed at centimetres wide