Narrow Leaflet Expression

Narrow Leaflet Expression refers to cannabis plants displaying notably thin, elongated leaf blades across the canopy—a trait often influenced by genetics, photoperiod, and growing conditions. This morphology is commonly associated with equatorial or tropical-origin lineages, where sativa-dominant genetics tend toward finer foliage. Breeders have observed narrow leaflets across several strain families, though the trait's heritability and environmental plasticity remain active areas of documentation. The expression can affect light penetration to lower canopy sites and alter the plant's overall structure during growth. Record-keeping among seed producers tracks this characteristic alongside other morphological markers to maintain consistency within curated lines.

Narrow leaflet expression is tracked by breeders working with sativa-forward or tropical-origin crosses, as it can influence canopy architecture and cultivation timing. Stabilizing or selecting against this trait depends on breeder goals for yield density, airflow management, and phenotype consistency in target growing environments.