The history of marijuana use reaches back farther than many would guess. Cultivation of the plant dates back thousands of years. The first written account of cannabis cultivation (ostensibly used as medical marijuana) is found in Chinese records dating from the 28th century B.C.E. And a nearly 3,000-year-old Egyptian mummy contained traces of THC, the main psychoactive chemical in marijuana, as well as other drugs .
Cannabis sativa is perhaps the world’s most recognizable plant. Pictures of the ubiquitous, green cannabis leaf show up in the news media, textbooks and drug-prevention literature. Its shape is made into jewelry, plastered on bumper stickers and clothing, and spray-painted on walls. The leaves are arranged palmately, radiating from a common center, like the fingers of a hand spreading apart. Although most people know what the cannabis plant looks like, they may know very little about its horticulture.
Believed to be a native plant of India, Cannabis sativa possibly originated in a region just north of the Himalayas. It’s an herbaceous annual that can grow to a height of 8-12 feet (4 to 5.4 meters), with reports as high as 20 and 25 feet (the indica variety tends to be squatter). The plant has flowers that bloom from late summer to mid-fall, when grown outdoors. Of course, plenty of people grow cannabis indoors, too. (See How Grow Houses Work for more information.)
Cannabis plants usually have one of two types of flowers, male or female, and some plants have both. Male flowers grow in elongated clusters along the leaves and turn yellow and die after blossoming. Female flowers grow in spike-like clusters and remain dark green for a month after blossoming, until the seed ripens. Hashish, which is more potent than marijuana, is made from the resin of the cannabis flowers.
As we mentioned, marijuana plants contain hundreds of chemicals, 109 of which fit into a category called cannabinoids. THC, of course, is one of these cannabinoids, and it’s the chemical most often associated with the effects that marijuana has on the brain. The concentration of THC and other cannabinoids varies depending on growing conditions, plant genetics and processing after harvest.
Seeds are produced in female cannabis plants and carry the genetics of a male and female. Seeds need to germinate to sprout and will grow a taproot, which will become the main root that anchors the plant.
These are the first leaves to grow from the seed after germination. They usually come in pairs, and seeing them is a sign of successful germination and that your plant is on its way to growing healthy and strong.
The roots grow down from the main stalk of the plant into the soil. When growing from a seed, the main root is called the “taproot.” Roots are the lifelines of a cannabis plant, pulling water and oxygen into the plant so it can grow healthy and strong.
Mycorrhizae, a beneficial fungus, can be added to soil to improve root systems.
The main stem, or stalk, of a cannabis plant grows straight up from the root system and supports all lateral branches. The stem gives a plant structure and stability.
Often, growers will top, or cut off, the stem after about five nodes, which forces the plant to grow out laterally more, creating more bud sites.
Branches grow out of the main stem and support fan leaves and buds. Growers often train a cannabis plant by topping branches to create more bud sites.
A node is a point at which a branch grows off of the main stem, or one branch from another branch. Fan leaves and buds can grow on some nodes, but not necessarily all.
When determining the sex of a cannabis plant, pre-flowers, or the beginnings of male and female sex organs, will appear at the nodes.
The space between nodes is called “internodal spacing” and will give you a sense of whether a plant will grow tall or short.
Fan leaves are the large, iconic leaves of the cannabis plant. They capture light for the plant and typically have little-to-no resin and are usually discarded when trimming.
Sugar leaves are the small, resin-coated leaves that buds form around. Sugar leaves are usually saved as “trim” during harvest and can be used for pre-rolls, extracts, and other cannabis products.
Also known as “buds,” the flowers of a cannabis plant are the fruits of your labor. They contain the cannabinoids and terpenes that get you high or offer health benefits. Flowers only grow on female cannabis plants and must be dried before consumption.
A cola, also called a “bud site,” refers to a cluster of buds that grow tightly together. While smaller colas occur along the budding sites of lower branches, the main cola—sometimes called the apical bud—forms at the top of the plant.
Bract and calyx
A bract is what encapsulates the female’s reproductive parts. They appear as green tear-shaped “leaves,” and are heavily covered in resin glands which produce the highest concentration of cannabinoids of all plant parts.
Enclosed by these bracts and imperceptible to the naked eye, the calyx refers to a translucent layer over the ovule at a flower’s base.
Stigma and pistil
The pistil contains the reproductive parts of a flower, and the vibrant, hair-like strands of the pistil are called stigmas. Stigmas serve to collect pollen from males.
The stigmas of the pistil begin with a white coloration and progressively darken to yellow, orange, red, or brown over the course of the plant’s maturation. They play an important role in reproduction, but stigmas bring very little to the flower’s potency and taste.
Despite their minute size, it’s hard to miss the blanket of crystal resin on a cannabis bud. This resin is secreted through translucent, mushroom-shaped glands on the leaves, stems, and calyxes.
Plants originally developed trichomes to protect against predators and the elements. These clear bulbous globes ooze aromatic oils called terpenes as well as therapeutic cannabinoids like THC and CBD. The basis of hash production depends on these trichomes and their potent sugar-like resin.
A 10,000-year-old archaeological site in Taiwan contains pottery fragments with a twisted strand imprinted around the edge, which some believe was made by pressing a rope made of hemp, the fibers made from the cannabis plant, across the wet clay, according to “Marijuana: The First Twelve-Thousand Years,” (Springer, 1980).
Hemp fabric was widely used in ancient China to make clothing. A Chinese medicinal textbook, the Pen Ts’ao, which is credited to an emperor in 2800 B.C., claims that “Ma,” or marijuana, was a powerful medicinal plant. Siberian burial mounds have traces of burnt cannabis seeds dating to 3000 B.C.
“We’ve had industrial use and medical use literally for millennia,” Earleywine told Live Science.
The plant was first given its taxonomic identification by Carl Linnaeus in 1753 and thoroughly described to Westerners in the 1800s, when the medical doctor William O’Shaughnessy gave a report to the Medical and Physical Society of Calcutta in India in 1839. The doctor described its effects on people and did a few case reports on “gunjah,” the Indian name for the drug.
“Almost invariably the inebriation is of the most cheerful kind, causing the person to sing and dance, to eat food with great relish, and to see aphrodisiac enjoyments,” O’Shaughnessy wrote in his paper, “On the Preparations of the Indian Hemp, or Gunjah.”
O’Shaughnessy also conducted some of the first clinical trials of the drug, giving tinctures to dogs, cats, mice and rabbits.
The drug first became popular in Europe when Napoleon’s troops returned from Egypt, Earleywine said.
The Cannabis plant can grow up to 18 feet tall. In the Americas, Cannabis extract was a popular medicinal drug in the 1800s. But in the 1900s, the tide began to turn against the drug. In the 1920s, Mexican immigrants became associated with the smoked, recreational version of the drug, and anti-immigrant sentiments fueled marijuana prohibition.
By the 1930s, marijuana was banned in 24 states. The newly minted Federal Bureau of Narcotics launched a campaign against the drug, and newspapers fueled hysteria with headlines like the 1933 Los Angeles Examiner’s “Murder Weed Found Up and Down the Coast — Deadly Marihuana Dope Plant Ready for Harvest That Means Enslavement of California Children.” By 1937, Congress passed the Marihuana Tax Act, which effectively banned marijuana except for a few medicinal purposes, according to “Smoke Signals: A Social History of Marijuana – Medical, Recreational and Legal” (Scribner, 2012).
In the 1950s, the Narcotics Control Act and the Boggs Act stiffened penalties for marijuana possession, with first-time offenses requiring two to 10 year sentences and a minimum $20,000 fine, according to PBS.org. Penalties were relaxed in the 1970s, but President Ronald Reagan increased federal penalties for marijuana possession in the 1980s. On the federal level, marijuana is now regulated under the Controlled Substances Act as a schedule 1 drug, meaning the government considers it to have a high potential for abuse with no legitimate medical or therapeutic uses.
However, numerous states have decriminalized or legalized marijuana. As of early 2017, 26 states and the District of Columbia have legalized pot in some form of medical and/or recreational use, with other states soon to follow.