Cannabis has been used by humans since antiquity. During the Neolithic period, it was used as a source of fibre, for the production of foodstuffs, oils and medicinal products and during sacred rituals, having been present in human societies ever since. Accordingly, researchers have always shown interest in understanding its nature, characteristics and properties.
Cannabis enthusiasts, too, can benefit from this knowledge, particularly with regards to the different parts that make up the plant and their specific role.
It is important to understand that most cannabis plants are dioecious, meaning there are significant differences between male and female plants. The ones that produce cannabinoid-rich flowers are female, and the ones that produce pollen sacs are male. It is possible for a plant to emerge hermaphroditic and be monoecious, meaning it will have both flowers and pollen sacs, but this happens less frequently.
Female plants garner most of the spotlight in the cannabis world, as they produce much higher levels of cannabinoids, including THC.
Male plants are seen as undesirable due to their low cannabinoid production, and that exposure to female plants will cause the females to seed. While this is bad for smoking, male plants play an important role in the cultivation and breeding process and are also used for their fibers. With that sorted, let’s move on anatomy of a plant.
This guide is intended to familiarize cannabis consumers old and new with all of the parts of our beloved cannabis plant from the ground up.
The taxonomy of cannabis
Cannabis is a dicotyledonous angiosperm plant belonging to the Cannabaceae family, which also comprises hops. According to a recent chemotaxonomic study, the original cannabis strain is native to Central Asia, more specifically to the region extending from the Himalayas to northwest China. Because of its ability to ‘escape’ from controlled farming areas to the wild, it is considered a semi-domesticated plant.
Botanically speaking, cannabis is a dioecious species, meaning it produces both male and female plants. However, there are also cases of hermaphroditic plants with male and female sex organs. These reproduce through self-pollination, forming flowers that contain seeds, and have the ability to pass on their hermaphrodite genes, characteristics that growers find highly annoying. Cannabis has an annual life cycle – it may live for longer in the subtropics and in artificially controlled environments – and nowadays grows virtually everywhere in the world.
Even if the first botanical classifications date back to the 18th century, the taxonomy of cannabis has always been a source of confusion. According to the latest classification, developed by Small and Cronquist, all cannabis strains come from the original species Cannabis sativa. As a result, Cannabis indica has been redefined as a subspecies.
While Cannabis sativa is found mainly in Europe and North America, where it is grown for seeds, oil, paper, cord and fabric, Cannabis indica grows naturally in large areas of the southern hemisphere, where it is used for medicinal purposes rather than for seed and fibre production.
Cannabis Plant Anatomy
The roots grow below the substrate surface – soil or otherwise – and have various functions, ranging from providing the plant with firmness to absorbing the nutrients necessary for growth. Roots draw water and other essential nutrients into the plant from the soil. As a seed grows, a main taproot will emerge and branch out into a fibrous network within the soil. Cannabis plants have small, whitish roots that like to fill their potting mediums. This creates a sponge-like root network needed to meet the plant’s high water demands.
Embryonic leaves are called cotyledons. These are formed during embryogenesis, together with the stem’s and the root’s meristems (the plant cells responsible for growth). Cotyledons grow using the energy stored in the seed, and are the first set of leaves to emerge after germination. Their green colour indicates the presence of chlorophyll, which allows these tiny leaves to perform photosynthesis during the first stages of growth. Their life cycle is very short, drying out as soon as the seedling grows its first serrated leaves.
Branches and Stems
Cannabis emerges from a single main stem that branches off on either side into leaf nodes. This main stem not only provides structural support, but also contains the vascular system of tubes that supply the rest of the plant with water and nutrients.
Cannabis plants can have many branches that grow from the main stem.
If the plant were a city, think of this as the main highway. Within the stem system is xylem, which moves the water and nutrients through the tubes.
A node can be defined as an intersection between the main stem and the branches, or between these and secondary shoots. Cannabis indica plants tend to produce more nodes, and are therefore bushier and less vertical than Cannabis sativa plants, which exhibit a more elongated shape with fewer nodes.
Most people know marijuana by the distinct shape of its fan leaves.
Being the most iconic part of the cannabis plant has led many people to incorrectly assume fan leaves are the part that THC comes from. In reality, fan leaves contain very low levels of THC. Cannabis leaves act like most leaves on plants and collect sunlight for energy. Leaves also shade the delicate buds and protect them from sunburn.
Pre-flowering, the modified leaf structures (called bracts) that house the potential pollen sacs or buds-to-be look quite similar. They are the small, pear-shaped bundles nestled where branches divert from the stem. If white, whip like hairs begin to surface from the bract, the plant is female. If the bract becomes more full and bulbous (sometimes referred to as crab claws) the plant is male and will produce pollen sacs.
Example of a male cannabis plant.
Sexing plants before the pollen emerges is key to maintaining a grow, as the pollen will spread easily to female plants and produce seeds. In addition to seeds, fertilized plants cease their resin production, meaning they aren’t as good to smoke. To avoid cross contamination, breeders must pollinate under intensely controlled conditions.
Cannabis flower is the most well-known aspect of the plant.
A cola is simply the flowering top of the female cannabis plant. Of course, topping or the application of LST or the ScrOG method will give rise to multiple tops. Nevertheless, the main top buds are all considered colas. Buds and nuggs are simply cover-all terms for all flowers, that emerge from bud sites throughout the stems. Look for a white hair emerging from the leaf node in pre-flower to confirm a female cannabis plant.
Male plants do not produce bud when they flower, which is usually a couple of weeks sooner than females. The male cannabis plants will not necessarily be the largest, most vigorous plants in the garden either. Males produce stamens with anthers packed with pollen.
It is always wise to postpone jumping to conclusions until pre-flowers can be discerned. If the white hair is absent and a cluster of grapes begins to protrude, then a male is present.
Pistils, Calyxes and Trichomes
Supported by small sugar leaves, these three important structures compose the cannabis flower itself.
Pistils are the “hairs” on the flower. They are the plant’s female sex organs, which collect pollen for fertilization after blooming. Early on, as flowering begins, the hairs will be white, but will mature in to red, brown or orange hues.
Contrary to popular belief, hairs play no part in THC production, and their prominence (or lack thereof) has no direct correlation to bud quality or resulting high – although they can make the buds look very pretty!
Calyxes constitute the majority of the bud and appear as compact teardrop folds. Distinct from the sugar leaves that grow amongst them, calyxes turn into the seed incubator on the female plant when fertilized. Unfertilized, they are the main trichome factories for cannabis.
Finally, though they are some of the smallest parts of the plant, trichomes are the star attraction. Trichomes are small, hair like structures that produce the resin of the cannabis plant, responsible for creating the psychoactive and medicinal effect that make it so famous. For the plant, these compounds act to fend of disease and infection, offer safety from UV exposure and act as a deterrent to predators.
There are actually three types of trichomes, varying in size, found on the entirety of the plant. However, the largest of these, capitate-stalked trichomes, are produced primarily on the calyxes and surrounding sugar leaves. Capitate-stalked trichomes contain the highest concentration of cannabinoids and terpenes. They begin clear, but will become white to cloudy at they develop, usually resulting in an amber hue.
We hope this guide has been helpful to you in understanding and appreciating the miraculous cannabis plant. Remember, almost every part of the marijuana plant is useful one way or another so be sure to take full advantage of it’s versatility!