internodi

Internodi, in botany often referred to as internodes in English, are the segments of a plant stem between two consecutive nodes. Nodes are the points on the stem where leaves emerge or where buds are located, and internodes link these nodes along the stem. Internodes themselves do not bear leaves; their length and arrangement influence the overall architecture and height of the plant.

The length of internodes varies widely among species and during development. In many plants, internodes elongate during active vegetative growth and shorten when growth slows or when plants encounter stress. Hormones such as gibberellins and auxins play key roles in promoting or restricting internode elongation, while environmental factors like light, temperature, and nutrient availability also affect their length. For example, shade-avoidance responses often lead to longer internodes as plants try to reach light.

Internode length has practical implications for plant form and stability. Long internodes can contribute to taller, more spindly stems that are prone to lodging, whereas short internodes tend to produce compact, sturdy growth. This trait is important in agriculture and horticulture: breeders may select for optimal internode length, and growers may manage crops through pruning, training, or trellising to influence stem elongation and light interception. In grasses, cereals, and woody species, internode length influences harvestability, airflow, and mechanical strength, making it a fundamental aspect of plant morphology and growth regulation.