Phenotypic Classification

Phenotypic classification in cannabis refers to the observable physical and biochemical characteristics expressed by a plant, regardless of its underlying genetics. These traits—including leaf morphology, plant structure, resin production, and terpene profiles—are shaped by both genetic potential and environmental conditions. Breeders and cultivators use phenotypic observation to identify desirable expressions within a strain or cross, selecting plants that demonstrate consistent traits across generations. Unlike genotype (the genetic code itself), phenotype represents what growers actually see and work with in cultivation. Understanding phenotypic variation is foundational to selective breeding, as multiple phenotypes can emerge from the same genetic lineage depending on growing conditions, stress responses, and epigenetic factors.

Breeders rely on phenotypic selection to stabilize desired traits within breeding lines—selecting mother and father plants based on observable characteristics like plant height, node spacing, resin density, and flowering time. Consistent phenotypic expression across successive generations indicates genetic stability and helps establish predictable cultivars for commercial and research use.