Rhizome
A few beloved spices come from rhizomes, namely ginger, turmeric, wasabi, galangal, and fingerroot.
A rhizome is a modified subterranean stem of a plant. Unlike a typical stem that grows upward and focuses on structural support and the transportation of water and nutrients between roots and leaves, rhizomes are both storage units and propagators. They hold nutrient reserves that allow the plant to endure adverse environmental conditions, and they can sprout new leaves, shoots, and roots from their nodes.
Since they are underground and thicker than typical stems, rhizomes are often mistaken for roots, but there are key differences there as well. While roots also anchor the plant, they are organs (not stems) specialized for water and nutrient uptake (absorption, not storage). They lack the nodes of a rhizome and thus cannot propagate shoots and leaves, only additional roots. Roots also primarily grow downwards into the soil, while rhizomes only grow horizontally.
