The potato, Solanum tuberosum is a staple food in temperate regions. It originated at high altitudein the Andes. The plant grows from buds (eyes) that produce vertical stems when the tuber is planted ( top right, two ). The stems form leaves above ground, and both roots and rhizomes ( underground stems ) below ground. During the growth period, the rhizomes develop swollen tips that become the crop of harvestable tubers.The picture shows four tubers. Two are still small (left, above and below centre). One is large ( a potato ), One is green, due to exposure to light at the surface. All the tubers are attached to rhizomes (white and unbranched) Throughout, the thinner branched strands visible are the roots of the plant, which absorb water and nutrients from the soil and maintain growth of the tubers.