Botanically speaking, hemp and cannabis are the same, as both are varieties of Cannabis Sativa. However, the law makes a very clear distinction between the two and, in many states, one is legal while the other is not.
Hemp Plants VS. Cannabis Plants
The composition of these plants, and more notably the tetrahydrocannabinol (THC) content, is the main differentiator.
Hemp refers to a plant that has lower than 0.3% THC by weight. THC is the main psychoactive compound in Cannabis Sativa, and at such low levels, it's unlikely to have an effect.
Over the last few years, hemp strains have been bred to generate high levels of cannabidiol (CBD) and other cannabinoids. These are thought to produce similar effects as THC, but without the strong, euphoric high or the side effects that go with it.
Cannabis or marijuana plants have more than 0.3% THC content by dry weight and are grown to produce recreational or medical effects.
Hemp and cannabis strains are often labeled as Cannabis Sativa, Cannabis Indica, or a hybrid of the two. Whether there is actually a difference between the two "varieties" is still up for debate. Regardless, smokers tend to report a significant difference in the effects or Sativa and Indica, suggesting the former is more uplifting while the latter is more sedating.
There is also something known as Cannabis Ruderalis. Some argue that Cannabis Ruderalis is its own species, while others suggest it is a subspecies of Cannabis Sativa.
Regardless of the strain or the amount of THC, all hemp and cannabis plants contain terpenes. These compounds are present throughout nature and impart certain aromas and flavors. Many of the terpenes present in hemp flowers, for instance, are also found in thousands of other plants and herbs.
In combination with cannabinoids like CBD and CBG, these terpenes are thought to provide something known as the "entourage effect", whereby multiple compounds combine to create a synergistic and beneficial effect.
It’s why many users report strong feelings of relaxation and euphoria following consumption of hemp, even though research suggests that standalone CBD tinctures don't always produce such effects.
Female Plants VS. Male Plants
In the production of cannabis and hemp, female plants are generally preferred. They produce more cannabinoids (including THC and CBD) and growers go to great lengths to ensure their crop is all or mostly female.
The purpose of a male plant is to pollinate, at which point the female plant produces seeds and a lot of its cannabinoid production is lost. This is okay for the production of hemp seeds and fiber, but it reduces the yield of CBD oil, hemp flower, and cannabis flower crops.
Final Thoughts: Key Differences
To summarize, the differences between cannabis and hemp lies in the chemical composition of the plants and generally refers to the levels of THC.
Thanks to the 2018 Farm Bill, hemp is legal. These plants are grown throughout the United States and are often loaded with CBD, producing CBD products like tinctures, oils, concentrates, and more. Hemp can also be used to produce hemp oil, seeds, and fiber, which is used for building materials, paper, and more.
Cannabis has high-THC levels, produces intoxicating effects, is used recreationally and medically, and is listed under the controlled substances act.
If the DEA breaks down your door and find your stash of cannabis plants, you can't simply claim that you're growing hemp. The plants may look similar on the outside, but once that THC reveals itself, you could be facing serious charges. In fact, legal hemp growers have to test their crops multiple times throughout the growing season and if any plants exceed 0.3 percent THC, they are destroyed.