Humboldt Seed Co. calls this one of its Signature Strains, saying growers created it by crossing Purple Panty Droppers with Razzleberry. Blueberry Muffin’s purplish buds smell like the fresh baked goods they’re named for and deliver 20% THC and 0.05% CBD, according to the breeder. Blueberry Muffin tends to produce uplifting effects.