Cannabis strains are either pure breeds or hybrid varieties of Cannabis, typically of the subspecies C. indica or C. sativa. Strains are developed to highlight a specific combination of properties of the plant or to establish marketing differentiation.
Strains names are chosen by their creators, and often reflect properties of the plant, such as taste (e.g. Blueberry Haze) or the origin of the strain (e.g. G13 x Haze).
A strain may refer ambiguously to a few different forms of cannabis:
A cannabis grower may grow a cannabis seed into a plant and find that this plant is unique in some way. The grower may make genetically identical clones of the plant and distribute these. This is technically referred to as a clone-only strain. A clone is the only way to propagate the exact genetic makeup that makes a strain unique, however, how the plant is grown greatly affects the final consumable product.
When a pot breeder wishes to develop a new stable seed strain, this process is more complicated and time consuming. It involves selectively choosing male and female cannabis plants and breeding them over the course of multiple generations. The final generation's seeds will have been stabilized by the breeder on the specific attributes chosen, though some genetic variation still exists among the seeds.
Unstable seed strains may be produced more quickly. However, plants grown from these seeds may have widely varying characteristics. Reputable seed shops will not distribute these unstable seed strains, though some amateur growers might. Third party growers may produce unstable derivatives from well known strains and misleadingly call them by their official strain name.
Some strains, such as Haze and Thai refer to cannabis plants found growing wild in certain regions. Typically, these plants are used as bases for the production of more specialized strains (e.g. G13-Haze).
Finally, black market cannabis dealers may distribute marijuana that is misleadingly called by a strain name. For example, Skunk and G13 may be used, but a lower grade may actually be sold.
Popular strains include:
007 (White Rhino + Red Widow + Skunk #1)
Afghani Goo (a.k.a. AfGoo) - hybrid strand, mostly indica
Blue Dream (Blueberry Surprise + Haze)
Blueberry Surprise - hybrid strain (80% indica/20% sativa)
Bubbleberry (Bubblegum + Blueberry)
Cherry Bomb (Lionheart + S.A.G.E.) - sativa
Ed Rosenthal Super Bud - hybrid strand, mostly indica, 25% THC, winner of the Cannabis Cup (1989)
Grand Daddy Purple
Great White Shark
Haze - sativa
High Plains Drifter
Holland's Hope - hybrid strain
If ya smoke me, you might get a little weird
Lionheart - sativa
New York City Sour Diesel - hybrid strand (40% indica/60% sativa)
OG Herojuana Panama Red
Purple Vampire Bitch
Quebec Gold (M39 + Friesland) - indica
S.A.G.E. (Sativa Afghani Genetic Equilibrium) - 2nd Place High Times Cannabis Cup (2001), 1st Place High Times Cannabis Cup Hash (2000)
Sheeka Deeka Freaka
Silver Pearl (Early Girl + Skunk #1 + Northern Lights) - hybrid strand
Super Silver Haze
Super Snow Cap
Trainwreck - Hybrid strand (90% sativa/10% indica)
White Rhino - indica
White Widow - indica
Whether Cannabis consists of a single species, Cannabis sativa L., or two or more closely related species is a contentious issue. According to botanists Small & Cronquist, the single species C. sativa is divisible into two subspecies, indica and sativa. Pure "sativas" are relatively tall (reaching as high as 4.5 meters), with long internodes and branches, and large, narrow-bladed leaves. The so-called "indica" strains are shorter and bushier, have wider leaflets, and are often favored by indoor growers. "Sativas" bloom later than "indicas," often taking a month or two longer to mature. The subjective effects of "sativas" and "indicas" are said to differ, but contrary to popular belief, the ratio of tetrahydrocannabinol (THC) to cannabidiol (CBD) in most named drug strains of both types is similar (averaging about 200:1). Unlike most commercial drug strains, indica landraces often consist of a mixture of plants with varying THC/CBD ratios. The relatively high CBD to THC ratio typical of hashish produced in regions where these landraces are grown (e.g., Afghanistan and Pakistan) is useful for treating insomnia. In addition to "pure indica" and "pure sativa" strains, hybrids strains with varying ratios of these two types are common. For example, the White Widow hybrid is purported to have about 60% "indica," and 40% "sativa" genetics. These hybrid strains have combinations of traits derived from both parental types.
Strains are named by the breeder or grower to differentiate one from another. In competitive legal markets, such as in Amsterdam, there is significant pressure to create unique strains that dominate the market. This results in a number of distinct strain names that may refer to very similar cannabis.
Likewise, when a strain becomes popular, many breeders and growers may produce variations of the same strain using the same or similar name. For example, the Sour Diesel indica strain that was popularized in the United States is only vaguely related to Reservoir Seeds' Sour Diesel. Soma Seeds sells a 40% indica / 60% sativa NYC Diesel that bears little resemblance to the original Sour Diesel.
Breeding involves pollinating a female cannabis plant with male pollen. This will happen naturally. However, the intentional creation of new strains typically involves selective breeding in a controlled environment.
Often male plants, once identified by their ball-like stamen, will be separated from female flowers. This prevents accidental fertilization of the female plants, either to facilitate sinsemilla flowering or to provide more control over which male is chosen. Pollen produced by the male is caught and stored until it is needed.
The seeds produced by a germinated female will be F1 hybrids of the male and female. These offspring will not be identical to their parents. Instead, they will have characteristics of both parents. Advanced techniques can stabilize certain characteristics.
Seed shops sell both pure strains that have specific aspects stabilized and lower quality unstabilized hybrids.
Well known cannabis breeders: