A runner, known technically as a stolon, is a specialized type of stem that grows horizontally away from a parent plant, acting as a natural mechanism for movement and reproduction. These creeping stems allow plants to rapidly spread and colonize new areas of soil. While many plants reproduce sexually through seeds, stolons facilitate vegetative propagation. This strategy is common in many familiar garden and wild species, allowing them to create new individuals without pollination.
What Runners Look Like
Runners are distinct because they grow along the surface of the soil or just slightly beneath it. The stolon is a slender, horizontal stem that originates from a bud near the base of the parent plant. Unlike the main upright stem, a runner is thin and elongated, often featuring small, scale-like leaves. The runner is segmented by specialized points called nodes, which are separated by internodes. These nodes possess the meristematic tissue necessary for new growth, as seen in the long, arching runners of a strawberry plant. The structure is adapted for reaching new territory quickly, rather than for structural support or food storage.
How Runners Create New Plants
The primary function of a runner is asexual reproduction, producing a genetically identical clone of the parent plant. This process begins when the slender runner extends outward, searching for a favorable spot to establish a new plant. When a node along the runner makes contact with the soil, it activates a biological response, forming adventitious roots that anchor the new plantlet. Simultaneously, a new shoot system develops upward from the same node. The parent plant supplies water and nutrients through the connecting runner until the new individual is established, after which the runner often breaks, creating a separate, self-sustaining organism.
Runners Versus Other Creeping Stems
It is common to confuse runners (stolons) with another type of creeping stem called a rhizome, but their main difference lies in their location of growth. Runners are defined by their horizontal growth above or directly on the soil surface. Conversely, a rhizome is a horizontal stem that grows underground, often mistaken for a root because of its subterranean habitat. Rhizomes, such as those found in ginger or iris plants, are thicker and fleshier than stolons because they serve as organs for storing carbohydrates and proteins. While both structures function in vegetative propagation, the runner is primarily a dispersal mechanism, while the underground rhizome offers better protection and acts as a survival mechanism.