Trans-caryophyllene α-Humulene, contributes to the characteristic aroma of Cannabis sativa Caryophyllene, with which some hashish detection dogs are trained Cannabis also produces numerous volatile sulfur compounds that contribute to the plant's skunk-like aroma, with Prenylthiol (3-methyl-2-butene-1-thiol) identified as the primary odorant. These compounds are found in much lower concentrations than the major terpenes and sesquiterpenes. However, they contribute significantly to the pungent aroma of cannabis due to their low odor thresholds as often seen with thiols or other sulfur-containing compounds. Common uses Cannabis sativa seeds are chiefly used to make hempseed oil which can be used for cooking, lamps, lacquers, or paints. They can also be used as caged-bird feed, as they provide a source of nutrients for most animals. The flowers and fruits (and to a lesser extent the leaves, stems, and seeds) contain psychoactive chemical compounds known as cannabinoids that are consumed for recreational, medicinal, and spiritual purposes. When so used, preparations of flowers and fruits (called marijuana) and leaves and preparations derived from resinous extract (e.g., hashish) are consumed by smoking, vaporising, and oral ingestion. Historically, tinctures, teas, and ointments have also been common preparations. In traditional medicine of India in particular cannabis sativa has been used as hallucinogenic, hypnotic, sedative, analgesic, and anti-inflammatory agent. Terpenes have gained public awareness through the growth and education of medical and recreational cannabis. Organizations and companies operating in cannabis markets have pushed education and marketing of terpenes in their products as a way to differentiate taste and effects of cannabis. The entourage effect, which describes the synergy of cannabinoids, terpenes, and other plant compounds, has also helped further awareness and demand for terpenes in cannabis products. Cultivation A Cannabis plant in the vegetative growth phase of its life requires more than 16–18 hours of light per day to stay vegetative. Flowering usually occurs when darkness equals at least 12 hours per day. The flowering cycle can last anywhere between seven and fifteen weeks, depending on the strain and environmental conditions. When the production of psychoactive cannabinoids is sought, female plants are grown separately from male plants to induce parthenocarpy in the female plant's fruits (popularly called "sin semilla" which is Spanish for "without seed" ) and increase the production of cannabinoid-rich resin. In soil, the optimum pH for the plant is 6.3 to 6.8. In hydroponic growing, the nutrient solution is best at 5.2 to 5.8, making Cannabis well-suited to