Can you name all of the parts of the cannabis plant? Can you explain what they all do? Do you want to be able to? This article gives an introduction to the anatomy of a cannabis plant, and whether you are a novice or a more experienced gardener, we hope you find it entertaining and interesting!
Roots
Appearance:
The roots of cannabis plants are long, white, and grow in a tangled mass directly down from the base of the plant. The main, thickest root is called the taproot and is the first root to appear when the seed germinates. That tiny thread develops into the main below-ground life support system for the whole plant.
The tap root, and the main roots, terminate in what is known as the root apex, which is tipped by the root cap. The root cap is a mass of cells which protect the hypersensitive tip of the roots, and also tell the plant which way is down – one of the reasons that it is important to be very careful with the ends of the roots!
The cannabis roots which grow at a rough perpendicular angle from the taproot are called the lateral roots. The entire root system is covered with a layer of fine white root hairs, so small that they can look like a coating of short silky fur. Although they are individually tiny, their combined surface area is far larger than it appears at first glance. This significantly increases the amount of water and nutrients that can be absorbed.
Role played in cannabis plant life cycle:
Cannabis roots absorb the minerals, nutrients and water from the substrate that the plant needs for photosynthesis, and store energy in the form of starches and sugars made by photosynthesis. Water is absorbed by cannabis roots in the bottom third of the root system, but they should never be left in a water-saturated substrate as they can drown in a matter of hours.
Oxygen is absorbed by specialized roots in the upper third of the root system. It is then used to convert the stored starch back into energy. This is especially vital during the flowering period, when the amount of photosynthesis that can occur is limited by the 12/12 light cycle so the plant relies on stored energy to create large healthy flowers.
Naturally, the other vital function of the cannabis plant’s root system is to keep it firmly anchored in its substrate. In free soil, some varieties, such as Durban, are capable of putting down tap roots up to two metres long, and others, like the Hindu Kush, can create a web that will withstand small storms.
Uses:
There are more uses for the roots of cannabis plants than many growers think! They are traditionally believed to have medicinal properties despite containing only miniscule levels of cannabinoids, and have been used in teas, poultices and even juice. This post goes into depth about the many uses of cannabis roots. And as a final tip, one of our commenters advises that the roots should be pulled on a New Moon, as this is when all the goodness is present in the highest quantities; this is a tip received from the Berber people of Morocco, who make frequent use of cannabis roots.
Stem and branches
Appearance:
Healthy cannabis plant stems can range in colour from vivid lime green to deep burgundy. In the early stages of growth, it is normal for them to appear a bit scaly, because the rate of growth outstrips the ability of the outer skin to stretch. On close inspection, a fine coating of tiny white hairs covers the stems. As the plant matures, vertical ridges from base to top become more pronounced.
The stem is divided by its nodes into sections called internodes. The nodes are the points at which the leaves, and later the branches, sprout out from the stem.
Role played in cannabis plant life cycle:
Healthy stems and branches are obviously essential for healthy buds! Not only do they transport essential building blocks of plant life to the leaves and flowers, they are the skeleton around which the buds will form. The stem of a cannabis plant is a highway for water, nutrients and minerals coming up from the roots in one direction, and newly produced starches and sugars that are not immediately converted into new plant matter going back down to the roots in the other.
In much the same way as human muscle is formed and increased by the muscle fibres tearing and then re-healing, cannabis stems and branches become thicker and stronger through the production of cellulose when the plants are moved by airflow. This is why it is essential to provide sufficient airflow for indoor grows; fans for ventilation are not usually sufficient to do this, so extra fans must create an artificial breeze. If the plants are visibly moving, this is a good indication that enough cellulose is being made.
In some varieties grown for extra large yields, such as Big Bud, the stems are sometimes not up to the task of supporting the weight of the buds even with enough air movement. Using stakes or plastic threads is usually sufficient to give enough extra help to the stems.
However, there is sometimes a good reason to (partially) break the branches on purpose. The technique known as ‘supercropping’ relies on the tops of branches being bent over to a 90 degree angle to the lower part. This creates a controlled, moderate amount of stress, causing the plant to produce extra branches and colas.
Uses:
If growing industrial hemp, the stems are one of the primary crops, highly valued for their bast fibres – the longest and strongest in the plant kingdom. Plants grown for this purpose can easily reach four metres in height, thanks to their exceptional stems.
Stems from plants from the psychoactive side of the family can be used to brew mild tea for the relief of headaches and nausea. Although there has, to our knowledge, been no large-scale testing of stems for their cannabinoid content, there have been some tests on stems. These revealed some THCA, negligible amounts of CBN and CBD, and surprisingly varied amounts of THC – out of three one-gram samples tested, two had barely any, but one contained over 80mg of THC
Leaves
Appearance:
The leaves are undoubtedly the most iconic part of the cannabis plant, almost universally recognised and adorning everything from t-shirts to tea-cosies. In their nascent stages, they have only one ‘leaflet’, or ‘finger’, as they are more commonly known. This number increases with the plant’s age and amount of leaves until usually about nine, although it can be as many as fifteen. These leaves are known as the feeder leaves, as their role is to feed the plant by soaking up as much light as possible.
The tiny leaves that protrude from the buds themselves in the later stages of flowering are known as the sugar leaves. This is due to their frequent coating of trichomes, giving the leaves a sparkling appearance as though they are coated with sugar.
More than any other parts of the cannabis plant, the leaves and the flowers vary in appearance depending on the strain, and on which part of the cannabis family the plant is from. Indica, sativa and ruderalis can all, with a little practice, be identified by their distinctive leaves. This diagram illustrates those differences, and this section of our Frequently Asked Questions explains them in more detail.
Role played in cannabis plant life cycle:
The appearance of cannabis leaves can also give very important indications of the overall health of the plant – what it might lack, and what it might be getting too much of, in terms of nutrients, minerals, water, heat, and light.
The main purpose of the leaves, however, is to act as the tiny green photosynthesis factories that convert water, brought to the leaves from the roots, and light, absorbed by the chloroplasts in the leaf, into chemical energy. This energy then combines with carbon dioxide, which enters the leaves through the stomata (tiny holes in the bottom of the leaf) to make sugars, which fuel the plant’s growth.
This post, one of our most frequently consulted, covers cannabis leaves in detail.
Uses:
In years gone by, the leaves were considered pretty useless unless they were attached to the plant and helping it grow. Now, we know better, as the benefits of juicing and even cooking with cannabis leaves are becoming more well known. The sugar leaves can be smoked, or used to make psychoactive edibles.
The fan leaves don’t have enough trichomes to make them worth smoking, and all they would do is give you a headache! However, we do have suggestions for other things to do with them. Many are mentioned in the post linked to above, and this video explores the health benefits of cannabis leaf juice.
Buds
Appearance:
Probably the most stared-at part of the cannabis plant, the flowers, or buds, can exhibit as many variations as roses, tulips, or any other flower bred for specific characteristics. They are also the part of the plant that displays its sex. Despite various urban myths to the contrary, the only way of telling whether a cannabis plant is male or female is to wait for the start of the flowering period, and examine the internodes.
This is the point where developing flowers could produce the tell-tale V-shape of white hairs that the majority of growers hope to see, and indicate the plant is female. If those hairs don’t appear, the emerging flowers will be male and eventually produce balls (a trait which makes it really easy to remember how to tell male from female).
As the buds thicken and grow, they cluster ever more densely around the stems to create the classic candle shapes known as colas. Looking at the buds closely, especially with a magnifying glass or loupe, reveals the trichomes. These tiny mushroom-shaped glands are where the cannabinoids are located, and are also responsible for the sparkling appearance of the buds.
The colours of these treasured flowers can range almost the full length of the colour spectrum, from almost white to almost black, with the most common shades between being greens, oranges, reds and purples.
Role played in cannabis plant life cycle:
The flowers are the reproductive organs of the plant. Cannabis is dioecious, which means plants are male or female, although they can also be hermaphrodite under certain circumstances. Once they are ripe, the balls produced by the male flowers open and release pollen which is carried by the wind (or by a clean paintbrush, if you’re a breeder) to the female flowers. Once it reaches the stigmas – the two hairs coming out of the pistil, the smallest part of the flower structure – it works its way to the egg cells, and a seed begins to form.
Seeds
Appearance:
Cannabis seeds vary in size from that of a large match-head to a little larger than a pin-head. Their colour is all the shades of brown, from tan to almost black, and often they are speckled or tiger-striped. The seeds are oval, rounded, and slightly flattened at one end with a point at the other. The skin has a slight sheen, and many people consider them to be as beautiful as the flowers, in their own way!
Role played in plant life cycle:
It all starts with a seed, as the saying goes! The seeds contain the precious genetic material plus all the stored energy needed to start the life of the plant. Germination is the beginning of that life; seeing the husk split open and the first tiny white root emerge is always exciting.
Uses:
Apart from the obvious use, which is growing cannabis plants, cannabis seeds are a rich source of nutrition due to their high oil content. If pressed to make hempseed oil, the husks that remain can be used as animal feed. The seeds can also be ground to make hemp protein powder. Naturally, the seeds used for nutrition are from industrial hemp plants rather than their more expensive psychoactive cousins!
We hope you have enjoyed this article, and maybe learned a few things along the way! Let us know in the comments below.
