The cannabis plant is comprised of harmoniously interconnected parts, much like other flowering species. However, as any medical patient, cannabis connoisseur, or recreational user knows, this plant—and its parts—are also categorically distinct.
Understanding the anatomy of the cannabis plant is crucial for growers, but users also benefit from a deeper look past the buds all the way down to the roots. If we are to truly appreciate and respect this therapeutic plant, it serves us to see what makes it so special.
The anatomy of a cannabis plant from the ground up
Arguably the most important part of any plant, the cannabis roots contain xylem that are responsible for bringing the soil’s nutrients and water to the main stem.
Cannabis roots begin as a single entity called a “tap root.” A healthy plant will quickly expand its root network with secondary roots growing from this primary tap root. Before too long, this network of roots can grow to nearly the same size as the mature plant.
Healthy roots are white and fibrous. Any browning or easy breaking can indicate poor soil conditions and even disease. Ensuring you’re growing in organic soil that is flush with fertility is the key to supporting a healthy root system.
The main stem supports the basis of all other parts of the plant. It reaches out from the root network beneath the soil and homes the nodes and branches. It serves as a vascular network, pumping the nutrients and water from the roots’ xylem to the rest of the plant.
A healthy main stem will be thick and sturdy enough to support the plant’s structure, including the bulky buds of the female species. If the main stem is flimsy, this will impede the rest of the plant’s ability to properly develop.
Nodes and branches
Nodes refer to the connecting part between the main stem and the branches. The branches serve as a supporting structure for the cannabis plant’s characteristic “fan leaves.” Branching in a healthy plant occurs in pairs—creating a balance on either side of the main stem.
You can use the branching spacing to determine whether the cannabis plant is indica or sativa. The spaces between branches are called internode spaces. Indica plants, known for their bushier nature than sativas, have shorter internode spaces between branches.
Fan leaves occur in male, female, and hermaphrodite cannabis plants. Even if you’ve never seen a cannabis plant in real life, you probably already have a clear picture of these leaves in your mind.
Inside the leaves is the phloem. The phloem acts much like the xylem in the roots. As the leaves absorb sunlight and undergo photosynthesis, the phloem transports that energy to the rest of the plant.
Over-pruning impedes the plant’s natural photosynthesis process and will result in a nutritionally-deficient plant.
These leaves are also indicative of the specific type of plant. Indica leaves are characteristically wider and darker than the skinnier and lighter green leaves of the sativa cannabis plant.
Flowers or “buds”
The flowers, or “buds,” are what separate the females from the males. In male species, which mature a few weeks sooner than females, you will find stamens and anthers containing pollen. The purpose of this plant is to fertilize surrounding females, but any grower knows this is not what you want. In fact, a fertilized female will direct her energy away from flowering and toward producing seeds.
The goal of growing is to develop healthy, hearty buds so it’s best to remove male plants from females as soon as you can tell the difference between the two. You’ll know for sure it’s a male if it lacks white hairs and starts producing what looks like a cluster of grapes rather than a flower.
Stigma and Pistil
Although you might not have heard its name before, you certainly know about stigmas. Stigmas are the hair-like substance on the flower. They grow on the pistil, or the part containing the reproductive components of the plant. Together, the stigma and pistil change colour as the plant matures: from white to yellow to orange to red, and finally, to brown.
Bract and calyxes
The flower of the cannabis plant is comprised of more than the stigmas and pistil. The bract encapsulates the pistil, but it is not one entity on its own. Rather, it’s made up of tiny teardrop shaped leaves that are concentrated with sticky resin and therefore, cannabinoids like THC and CBD.
The calyxes also play an important role in the anatomy of the cannabis plant. It serves as a translucent protective layer over the ovule at the flower’s base. This is where the pistils will grow from to capture pollen.
Trichomes are the miniscule sugar-like “crystals” that form the basis of the sticky resin residue that people process into kief and hash. Within this resin is potent terpenes and cannabinoids used for recreational and therapeutic purposes.