Anthocyanin Flavonoids

Anthocyanins are water-soluble flavonoid pigments responsible for red, purple, and blue coloration in cannabis flowers and leaves. These compounds are not terpenes in the strict sense, but rather phenolic metabolites often discussed alongside aromatic compounds in cannabis chemistry. Anthocyanin expression is primarily regulated by genetics and environmental factors—notably cooler temperatures during late flowering, which can trigger pigmentation in anthocyanin-rich cultivars. Breeders working with purple and dark-hued phenotypes typically select for genetic predisposition to anthocyanin accumulation. Historical cannabis landraces from high-altitude or cool-climate regions often carried stronger anthocyanin genetics.

Breeders pursuing visually distinctive cultivars—particularly purple, black, and deep-blue phenotypes—intentionally cross lineages known for anthocyanin expression. Anthocyanin intensity serves as a visual marker for phenotype selection across generations, though expression requires both genetic potential and environmental stress conditions (chiefly temperature drops) to manifest fully.