Cannabis is an annual, herbaceous, dioecious, (sexually differentiated) woody plant. It grows outdoors in temperate climates worldwide on all continents except Antarctica. Cannabis is grown intentionally indoors in many countries in clandestine operations.

Cannabis can be subdivided into 3 main species:

1. Sativa,

2. Indica, and

3. Ruderalis.

Each species carries unique genetic, botanical and biochemical traits. Breeding programs in the United States, Canada, Holland and Switzerland have resulted in hundreds of unique cultivars, plants selected for specific characteristics like floral appearance, THC content, disease resistance, size or vitality. These strains are grown in seed-breeding facilities in Holland, Canada and Switzerland by crossing different varieties to bring out some desirable trait. The genetic makeup of the parent plant determines the potency and other individual traits. Optimal growing conditions allow the potential of the genetics to develop. Sativas are large plants grown in South and Central America. Sativas can often reach 8 feet tall outside with branching habit that resembles a Christmas tree. Large stature is not desirable for indoor cultivation therefore breeders have crossed sativas with smaller sized indicas. Indica plants are common in India and Afghanistan. Ruderalis, the third and less common species, originated from northern Europe.

It is notable for early flowering characteristics and thin-leafed appearance. The unique chemical constituents of Cannabis are termed “Cannabinoids.” Cannabis contains some 60 cannabinoids that modify and contribute in complex ways to the medicinal or therapeutic properties.

The highest-concentration cannabinoid present in Cannabis is termed Delta-9-tetrahydrocannabinol, or “THC.” Other cannabinoids (than THC) are present in smaller amounts.

Cannabinoids are present in the leaves and flowers of the plant to varying degrees. The highest concentration is found in the unfertilized flowers (called “sinsemilla”) which have been harvested, dried and cured at peak cannabinoid production. Sinsemilla is quality Cannabis because the process of forcing flowers causes layer after layer of resinous buds to form. These are harvested when morphological changes indicate peak floral maturity and highest cannabinoid content. Left unharvested, the flowers begin physical and chemical decomposition as the plant enters “senescence,” its decline towards death. Senescence is sometimes interrupted by growers who “force’ the harvested plant to grow new leaves, a process called “regeneration”.

THC concentration represents the fraction (or percentage) of THC in relation to all the cannabinoids present. Ten percent (10%) THC concentration means that ten percent of all the cannabinoids present are THC. (Ninety percent are other cannabinoids.) THC concentration can range from 0.02% (hemp) to 15-30% for some Dutch and Canadian hybrids. The U.S. government grows 2-4% THC Cannabis at a research farm in Mississippi. This Cannabis is of poor to medium quality, and is considered harsh and difficult to smoke by the few patients still enrolled in the Investigational New Drug Program.

Outdoor growers in Oregon should, if possible, select Cannabis strains which will flower in their shorter growing season. Since Cannabis has acclimated to climates from equatorial to Northern and southern, its flowering pattern will follow these genetic tendencies. Thus, an equatorial variety that is accustomed to long slow flowering may not ripen in time if grown outdoors in Oregon.