internodes

Internodes are the segments of a plant stem between two consecutive nodes, the points where leaves, buds, or branches attach. The length of internodes contributes to the overall height and the spacing of leaves along the stem, shaping the plant’s architecture.

Internodes form during primary growth as the apical meristem elongates stem tissue. Their length varies with species, developmental stage, and position on the stem. In many herbaceous plants, internodes can be relatively long and flexible, while in woody plants, secondary growth enlarges the stem girth and can influence how much the internodes extend.

Internode length is influenced by genetics and environmental conditions. Factors such as light quality and intensity, photoperiod, temperature, nutrient and water availability, and mechanical constraints can alter elongation. Hormones play a key role; gibberellins promote internode elongation, and shade or low light often triggers shade-avoidance responses that lengthen internodes.

The length and arrangement of internodes affect plant performance, including light interception, canopy structure, and lodging resistance. Breeders may select for shorter internodes to enhance stability in dense crops or for longer internodes to promote vertical growth in climbing plants. The term internode is contrasted with the node, the attachment point for leaves, buds, or branches; the distance between consecutive nodes is the internode length.