Stem Pigmentation

Stem pigmentation refers to the coloration of plant stems, ranging from green to purple, red, or dark burgundy hues. This trait is controlled by anthocyanin and other pigment expression in plant tissues, influenced by both genetics and environmental factors such as temperature, light exposure, and nutrient availability. Breeders have documented stem pigmentation across many cannabis lineages, with some families consistently expressing darker stems while others remain predominantly green throughout growth. The trait appears in both photoperiod and autoflowering varieties, though expression intensity varies significantly. Stem color is often used as a secondary phenotypic marker alongside leaf and flower characteristics during cultivar selection and breeding programs.

Breeders track stem pigmentation as a visible genetic marker to identify and stabilize desirable phenotypes within crosses. While not a primary selection criterion, consistent stem coloration can indicate genetic stability and help distinguish phenotypic expression across generations.