Anthocyanins

Anthocyanins are water-soluble pigments responsible for red, purple, and blue coloration in cannabis flowers, leaves, and sometimes stems. These compounds are flavonoids—secondary metabolites distinct from cannabinoids and terpenes—and their expression depends on genetics, pH levels, temperature stress, and light exposure. Anthocyanin-rich strains have been selectively bred for decades, particularly in lineages tracing to Purple Haze, Blueberry, and Granddaddy Purple. While pigmentation is purely aesthetic in breeding terms, it serves as a visible marker of genetic stability and can indicate cold-weather adaptation in some cultivars. Breeders often preserve anthocyanin traits through selective cross-breeding and environmental manipulation during flowering cycles.

Breeders working with anthocyanins focus on stabilizing color expression across generations, as pigmentation can be unstable without careful selection. Anthocyanin traits are frequently crossed into modern hybrids to retain visual distinctiveness and market differentiation, though expression requires precise environmental control—particularly cooler night temperatures during late flowering.