A stolon is a specialized, slender stem that develops horizontally, either along the surface of the soil or just below it. This structure is a primary mechanism for asexual reproduction, allowing the plant to clone itself without seeds or sexual fertilization. Stolons are often called “runners” because their creeping growth habit allows the plant to spread rapidly and colonize new territory.
Structure and Purpose of Stolon Growth
The stolon is a modified stem that originates from an axillary bud at the base of the parent plant. Unlike the main upright stem, the stolon elongates horizontally, often having long internodes, which are the segments between the nodes. The nodes along the stolon are the sites of regeneration, where the plant initiates new growth that will become an independent clone.
When a node makes contact with suitable substrate, it develops adventitious roots, which are roots that arise from a non-root tissue, and a new upright shoot. This process of forming a new, self-sufficient plantlet is hormonally regulated. The stolon acts as a temporary conduit, transferring nutrients from the parent to the developing ramet until the new plant establishes its own root system. Once established, the stolon connecting the two often withers and decays, making the new plant a distinct, separate individual.
How Stolons Differ From Similar Plant Parts
Stolons are often confused with other horizontal plant structures, particularly rhizomes, but their location provides clear distinctions. Stolons typically grow above ground or creep just along the soil surface, while rhizomes are subterranean stems that grow horizontally underground. This difference in location influences their primary roles.
Rhizomes are generally thicker and contain stored carbohydrates, serving both as a means of vegetative propagation and as a storage organ for perennation. Stolons, in contrast, are usually thinner, have less storage capacity, and are dedicated to rapid spatial spreading, seeking out light and new resources. While both structures have nodes and internodes and produce new plants, the rhizome’s dense, underground nature contrasts with the stolon’s slender, surface-level design.
Common Plants That Use Stolons for Propagation
Many common plants rely on stolons for propagation, with the strawberry plant being the most widely known example. Strawberry plants (genus Fragaria) produce visible, arching stolons, or runners, that extend outward from the main crown. These runners travel a short distance, and a node along the stem establishes a new plantlet that roots into the soil, allowing a single parent plant to quickly cover a wide area.
Certain turfgrasses, such as Bermuda grass (Cynodon dactylon), also utilize stolons for their dense, creeping growth habit. The stolons of these grasses spread across the lawn surface, rooting at the nodes to fill in bare patches and create a thick mat. Even some ferns, like the Boston fern (Nephrolepis exaltata), produce fine, slender stolons that trail away from the parent plant, with new fronds and roots emerging from the tips.