Exactly what are trichomes? If you’ve ever had the opportunity to take an up-close look at a cannabis plant, you’ve probably noticed the small, crystalline, hair-like structures that cover its leaves and flowers. They’re known as trichomes, and they play an extremely important role in the chemistry of cannabis.
When it comes to cannabis, trichomes are where the magic happens. These tiny crystalline structures are where cannabis compounds are produced, including the cannabinoids, terpenes and flavonoids that contain the wellness-promoting benefits that put CBD products on the map.
If you’re one of the countless members of our community who enjoy taking CBD on a regular basis, you’ve got trichomes to thank for it. Through the natural process of biosynthesis, the first cannabinoid to form within trichomes is CBGA (cannabigerolic acid), which is the precursor to all other cannabinoids.
We’ll take a detailed look at trichomes for a better understanding of the role they play when it comes to cannabis.
What are Trichomes?
Trichomes aren’t just found in cannabis. The word “trichome” stems from the Greek word tricoma which means “hair.” The official definition of trichomes is “fine outgrowths or appendages on plants, algae, lichen and certain protists.”
When viewed under a microscope, trichomes look like hairs with a bulbous tip and somewhat resemble the shape of a mushroom. These resinous glands typically range between 10 and 100 micrometers in width. They completely cover the flowers and leaves of the budding plant.
Trichomes emerge when the cannabis plant moves into the flowering stage. As cannabis flowers begin to bloom, trichomes take shape on the buds, leaves and stalks of the plant.
What is Their Function?
Trichomes are extremely diverse and serve a wide range of functions that vary between plant species. The location, size, density and form of trichomes on various plants provide different advantages.
What exactly do trichomes do?
These tiny, resinous hairs can be considered a plant’s first defense mechanism. They deter certain herbivores, can deter frost from surface cells, disrupt the flow of air when it’s windy and reflect UV rays.
This defense is especially helpful for cannabis plants which become susceptible to insects and animals when grown in the wild. The trichomes help protect cannabis flowers from animals with their pungent smell and bitter taste, and from the wind and strong UV rays that might otherwise cause damage.
In carnivorous plants, trichomes help to catch prey. Take the Venus flytrap, for example. The “trap” consists of two hinged lobes at the end of each leaf. On the inner surface of these lobes are trichomes that make the lobes snap closed to trap prey.
Different Types of Trichomes
There are different types of trichomes, such as stinging hairs, glandular trichomes and scale or peltate hairs. Cannabis contains different types of trichomes which belong to two different categories: glandular and non-glandular. The only type of trichome that produces cannabinoids and other cannabis compounds are glandular trichomes. Trichomes found on cannabis include:
- Bulbous trichomes
Bulbous trichomes are the smallest of the three types of trichomes found on cannabis plants. Almost invisible to the naked eye, they only reach a size of 10 to 15 micrometers and cover the entire cannabis plant.
- Capitate-sessile trichomes
Capitate-sessile trichomes are slightly larger than bulbous trichomes, reaching a size of approximately 25 to 100 micrometers. They contain a single-cell stalk and bulbous head and are found in greater abundance in cannabis than bulbous trichomes.
- Capitate-stalked trichomes
Capitate-stalked trichomes are the largest and most abundant trichomes found on the cannabis plant. These trichomes are the ones visible to the naked eye and are considered the most important, as they’re where the most abundant concentrations of cannabis compounds are found. The stalk of capitate-stalked trichomes is prominent, and the head is significantly bulbous.
How Cannabis Compounds are Created
You may have already heard of the term biosynthesis. Biosynthesis is the process in which complex structures are built out of simple ones. Cannabinoids, terpenes and flavonoids are produced in the trichomes through the process of biosynthesis.
There are three basic steps that take place in trichomes during biosynthesis to produce these cannabis compounds:
- Binding: When microscopic enzymes bind to one or two small molecules, known as substrates.
- Prenylation: When substrates attach to each other, causing a chemical conversion of the substrates.
- Cyclization: When the transformed substrate is passed to another enzyme, where it is further processed and subsequent changes are made.
The photosynthetic process takes place in the secretory vesicle within the trichome gland head. As the cannabis plant grows, cannabinoids, terpenes and flavonoids accrue along the outer cuticle of the trichome. As the secretory vesicle creates oil, it is pushed toward the cuticle of the trichome head causing it to grow thicker and more bulbous.
We mentioned that trichomes appear during the flowering stage of cannabis growth. At the beginning of this stage of growth, trichomes are usually clear or faintly amber. Just before harvest, when cannabinoid, terpene and flavonoid levels reach their peak, the gland head of the trichome will turn opaque or cloudy. This is when cannabinoid levels reach full maturity and generally when plants are harvested for maximum cannabinoid levels.
Trichomes and the Creation of Cannabinoids
The first cannabinoid to develop in trichomes is CBGA. Consider CBGA the foundation on which all other cannabinoids are created. The “A” stands for acid, indicating the presence of a carboxylic acid group, which is also the case for other cannabinoids that end with an “A.” The carboxylic acid group is dropped when heated, a process known as decarboxylation.
CBGA is formed within trichomes through an intricate chain of biosynthesis reactions where geranyl pyrophosphate and olivetolic acid bind to each other. This is done with the help of an enzyme known as GOT.
Once geranyl pyrophosphate and olivetolic acid have come together to form CBGA, the complex process of biosynthesis continues. As CBGA goes through the process of cyclization, or the formation of one or more rings in a chemical compound, other cannabinoids begin to take shape in their acidic form.
THCA (tetrahydrocannabinolic acid), CBDA (cannabidiolic acid) or CBCA (cannabichromenic acid) are created with enzymes referred to as THCA synthase, CBDA synthase or CBCA synthase. Which cannabinoid is the most dominant is largely determined by the existence and comparative quantities of specific enzymes.
Trichomes: A Vital Aspect of the Complex Cannabis Plant
Most of us who take CBD on a regular basis don’t think of the complexity that goes into its creation. The many benefits CBD, however, wouldn’t be possible without the presence of trichomes. We hope you enjoyed learning more about the biological process that occurs within the cannabis plant that forms the basis for its wellness-promoting potential.