The part of the potato plant we eat is called a tuber. This is actually an enlarged underground stem. Each plant will produce multiple tubers. Potato tubers come in a variety of colours, but the most common are red and white. Their shape can be round, oblong, flattened or elongated. An identifying feature of potato tubers is their ‘eyes’, which are small nodes with buds. If tubers are placed in a warm location, the buds will sprout. If tubers are exposed to light, the buds and the tuber itself will turn green.