Trichomes are the tiny, transparent hair-like glands that give cannabis flowers their sugary appearance. Trichomes are found all over the cannabis plant, but are most prominent on the flowers. Cannabis growers prize trichomes for their high concentration of cannabinoids and terpenes – it’s a good sign if a cannabis flower has the frosty white coating characteristic of large amounts of trichomes.
As well as providing us with a high concentration of tetrahydrocannabinol (THC) and cannabidiol (CBD), trichomes help defend the plant against the environment and pests. There are several different types of trichomes, and cannabis growers use them to determine when a plant might be ready to harvest.
To better understand the role trichomes play, it can be useful to understand a cannabis plant’s anatomy and where trichomes fit into the bigger picture.
The Anatomy of a Cannabis Plant
Cannabis plants have a rigid main stem that grows directly upwards. Branches extend outwards from the main stem, with flowers and leaves growing from these branches. Cannabis plants naturally grow tall and straight, but growers often keep them short so they grow broader with more flowers.
Areas along the main stem from which branches grow are called nodes. Nodes are also where leaves and, eventually, flowers develop. The lower nodes will produce fan leaves, which are the distinctly shaped, pointy leaves that many people associate with cannabis. Higher up are sugar leaves, which the flowers form around.
At a cannabis plant’s apex you’ll find the cola, which is a large cluster of flowers or ‘buds’ that are densely packed with cannabinoids and terpenes. There can be more than one cola on a cannabis plant, but the biggest is typically found at the top where the plant receives the most light and nutrients.
At the base of the flower itself, you’ll find bracts – small, leaf-like structures that protect the flower. Surrounding the flower’s reproductive organs is the calyx, which are small sacs covered in trichomes that contain the highest concentration of cannabinoids and terpenes found anywhere on the plant.
Cannabis plants also have stigmas, which resemble tiny hairs. Stigmas use their sticky texture to capture airborne pollen from male plants. From here, the pollen travels down the style – a slender tube – and is delivered to the plant’s ovary where fertilisation occurs. This whole system makes up what’s called a ‘pistil.’
Are There Different Types of Trichomes?
There are many different types of trichomes in the plant kingdom, but cannabis tends to have three main types: bulbous, capitate-sessile and capitate-stalked.
Bulbous trichomes are rarer than other types of trichomes and contain fewer cannabinoids and terpenes. They have a spherical head atop a short stalk and are almost too small to see with the naked eye – sometimes measuring only 10 micrometres wide.
Capitate-sessile trichomes are typically around 20 to 30 micrometres wide and consist mainly of a large head and very small stalk. They are richer in cannabinoids and terpenes compared to bulbous trichomes, and are mainly found on the leaves and stem of a cannabis plant.
Capitate-stalked trichomes are the largest and most abundant type of trichome on cannabis plants. They are prized by growers for their high concentration of cannabinoids and terpenes, and together they form the crystalline coating seen on mature cannabis flowers and sugar leaves. They can range from 200 to 300 micrometres tall, with a long stalk and glandular head.
What Uses do Trichomes Have?
Trichomes are where growers source the compounds used to make medical cannabis products, but they are also a vital protective component of a cannabis plant’s anatomy.
Trichomes form a sticky barrier between cannabis plants and the environment, which can deter or trap insects. The cannabinoids and terpenes in trichomes also have a bitter taste and a pungent aroma that may stop larger predators from interfering with the plant, or the smell might attract certain pollinators. Trichomes also help the cannabis plant retain moisture while simultaneously protecting the delicate flowers from harsh sunlight, heat and UV radiation.
As trichomes get older they become cloudy, which indicates that they are beginning to create cannabinoids. Eventually, trichomes become amber coloured, which typically means that the THC within the trichomes is beginning to degrade to cannabinol (CBN). Cannabis growers often closely monitor trichomes for these changes in appearance, as it can be a good way to measure the best time to harvest.
You can still see trichomes on a cannabis flower even after it’s been dried and cured. Within these trichomes and the plant material itself are the cannabinoids and terpenes you can consume via inhalation with a medical cannabis vaporiser. Alternatively, growers will grind up the cannabis flower and trichomes and place the ground material into a solvent such as ethanol, which extracts the cannabinoids and terpenes. Manufacturers then make oil, creams, tinctures and more out of the extracted cannabinoids and terpenes.
What Causes a Cannabis Plant to Produce Trichomes?
Cannabis growers use several techniques to produce plants with lots of trichomes. Firstly, they source high quality seeds from a strain that tends to produce many trichomes. Then, growers will ensure that the lighting and nutrients are optimal for each plant to flourish.
Controlling the temperature and humidity is also vital, and some growers use a technique called ‘cold shocking,’ where they lower the temperature when the plant is in its late flowering stage. Cold shocking often results in more trichomes.
Growers will also prune cannabis plants to give them more light and airflow, which may also increase trichome production. Another technique is intentionally stressing the plants by slightly overfeeding them or reducing humidity, which can cause more trichomes to develop as part of the plant’s defence mechanism.
Growers will often use several of these techniques to produce plants with as many trichomes as possible, since more trichomes equals more cannabinoids and terpenes.
Trichomes: a Vital Part of The Cannabis Plant
Trichomes provide us with the valuable compounds that help many people across Australia. However, they are also a vital component of the anatomy of cannabis, serving many purposes beyond just producing THC, CBD and terpenes.
If you ever receive a medical cannabis prescription, trichomes will have played a large role in the creation of whichever product you receive. If you have a medical condition that hasn't responded well to conventional treatments, you may be eligible for a medical cannabis prescription.
Speak with your doctor or make an appointment with a medical cannabis clinic if you’d like to learn more about THC, CBD and the other cannabis compounds that trichomes play a vital role in producing.
Explore Medical Cannabis Flower For Yourself
It's thanks to the resin-producing trichomes that cannabis flower and its many related products are thought to offer therapeutic value. If you’re wondering whether medical cannabis could be helpful for your chronic condition, book a consultation with a doctor at a cannabis clinic or your local GP. They'll be able to assess your history and symptoms and make a decision as to whether you're eligible – and could benefit from – cannabis care.
There are a number of risks associated with the use of medical cannabis and your doctor will explain these to you before issuing a prescription. Medical cannabis affects everyone differently and may not help with your chronic condition.