Sour Diesel, sometimes abbreviated as Sour D, is an extremely popular strain, distinguished by the fuel-like chemical smell of its flowers. It has a mostly sativa head high with some subtle physical indica relaxation, making it popular among recreational and medical users alike. This is a potent strain, with a THC content that had been measured at between 20% and 25%. Because the underground cannabis market of the 1980s and 90s operated without any kind of lasting documentation, the exact origins of Sour Diesel are not known. Although a definitive agreement on its original genetic makeup doesn't exist, Sour Diesel’s popularity has made it the subject of much speculation. Some believe that true Sour Diesel was derived as a distinct phenotype of an original strain simply named Diesel. Others say that it was a phenotype of Chemdawg that leaned more sativa than indica. Still others claim that it was a cross of Chemdawg and Northern Lights, or perhaps Chemdawg, Northern Lights and Skunk #1. Sour Diesel has round, medium-sized buds with leaves that appear yellowish-green. Red hairs called pistils, structures that operate to catch pollen from male plants, contrast with the densely-packed leaves. When properly cured, the flowers are somewhat sticky -- the dusting of trichomes is not as immediately obvious as it is on more resinous strains like White Widow. Nevertheless, breaking open buds reveals trichomes coating the insides of the dense flowers. The buds have an overpowering smell that, true to this strain’s name, is very similar to gasoline. The odor also has some hints of orange. Breaking open or grinding the buds intensifies this scent, and adds components of musk and pine sap. Sour Diesel has a notoriously harsh, acrid smoke that can cause users to cough or make their sinuses water. The smoke has a sour and vaguely skunky taste that may describe as unpleasant; on the exhale, the diesel and almost ammonia-like tang stings the palate and may linger for a long time afterward. Smokers trying to remain discreet should be warned that this is a very pungent strain whose odor can carry for quite a distance.