Fan Leaf Blade Count

Fan leaf blade count—the number of leaflets radiating from a petiole—is a discrete morphological trait commonly used in cannabis taxonomy and breeding documentation. Plants typically display between 5 and 13 blades per fan leaf, with 7-9 being most frequent in indica and sativa-dominant cultivars. This trait is determined by polygenetic inheritance and environmental factors, making it useful for identifying cultivar lineages and distinguishing phenotypic variation within a genetic population. Breeders have long recorded blade count as a simple, visible marker for tracking parental genetics and F1 stability. Historical seed catalogs and herbarium records frequently reference leaf morphology as a preliminary classification tool before molecular genotyping became standard.

Leaf blade count serves breeders as a quick visual marker for phenotypic consistency and hybrid vigor assessment across generations. Consistent blade morphology across a cohort can indicate genetic stability and homozygosity at relevant loci, making it valuable for F1 standardization and parent selection.