Weed trichomes are hairy, bulbous structures which cover the surface of cannabis flowers and leaves. These trichomes produce terpenes, which give weed its distinctive scent. They also contain cannabinoids- chemicals that have a wide range of effects on your body and mind when they’re consumed. Cannabis is made up of about 60% THC, 40% CBD at a rough estimate. The ratios in each strain vary depending on how it was grown and what type it is (indica vs sativa). THC binds to cannabinoid receptors in your brain- producing euphoric feelings and altering your senses.
An appendage on the surface of the cannabis flower that produces and holds the plant’s cannabinoids and terpenes. Trichomes are primarily produced on the flower, bract, and leaves of the cannabis plant. They have a sugary, crystal-like appearance.
This bud is covered in trichomes. Look how frosty and sticky it is.
If you’re going to make dry sift, use freeze-dried cannabis so the trichomes break off the plant more easily.
The actual definition of trichome is “fine outgrowths or appendages on plants, algae, lichens, and certain protists.” Originating from the Greek word “Tríchōma,” meaning “growth of hair,” these tiny microscopic mushroom-looking protuberances look like something out of a science fiction novel. But they are actually the very factories that produce the hundreds of known cannabinoids, terpenes, and flavonoids that make our favorite cannabis strains potent, unique, and effective.
The function of trichomes on cannabis
The production of trichomes can be observed in many species of plants throughout nature, taking on various physical forms as well as serving many different purposes. For example, trichomes found on some carnivorous plants aid in helping to catch prey.
In cannabis, trichomes function as a defense mechanism. When female cannabis plants begin to produce flowers in the wild, they often become vulnerable to various insects and animals as well as non-living environmental variables such as potentially harmful UV rays. Trichomes serve as a deterrent for animals because their bitter taste and strong aromas render cannabis flowers unpalatable. At the same time, they also serve a dual function in protecting their plants from damaging winds and even some varieties of fungal growth.
The different types of trichomes on cannabis
Trichomes exist in many shapes and sizes, but there are three that appear most often on cannabis plants.
- Bulbous trichomes are the smallest of the bunch, and they appear on the surface of the entire plant. Bulbous trichomes are as small as 10-15 micrometers, which is tiny enough to only be comprised of a handful of cells.
- Capitate sessile trichomes are slightly larger and contain both a head and a stalk. These trichomes are quite a bit more abundant than their bulbous brethren, but cannot hold a candle to the bountifulness and size of the third trichome variety.
- Capitate-stalked trichomes range from anywhere between 50-100 micrometers wide, meaning they’re much larger and can actually be seen by the naked eye. Their structure consists of a stalk comprised of epidermal and hypodermic cells that build up to a basal cell which attaches to a large gland head. This gland head, held together by a waxy cuticle layer, serves as the epicenter for cannabinoid and terpenoid synthesis.
All three types of trichomes produce cannabinoids, though it is the capitate-stalked trichomes that will appear in abundance in and around the calyxes of budding flowers, producing the highest concentration of essential oils due to their size.
Trichome production and lifecycle
Cannabinoid synthesis within the trichome begins as cannabis plants move into their bloom phase. As they begin to produce flowers, trichomes form along the outer surface of the above-ground plant vegetation and begin to transport vacuoles and plastids from their stalk into the gland head. At this point, cells within the gland head will begin to metabolize and form precursors for what will eventually become cannabinoids.
The rate and concentration at which a cannabis plant produces trichomes will be contingent on both genetics well as some environmental factors. Though plants containing higher concentrations of trichomes don’t always produce the highest concentration of cannabinoids and/or terpenes, variables such as UV light greatly affect cannabinoid and terpene synthesis within the trichome head. Typically, plants that receive a broader spectrum of light will produce higher concentrations of cannabinoids, though in many cases these reactions will be strain-specific.
A trichome’s lifecycle largely parallels that of the cannabis plant on which it resides, making it incredibly valuable for farmers to monitor. The life of a trichome can be analogous to a parabola, where the apex represents the point at which maturation exceeds and degradation begins. For the most part, trichomes will display maturation on this parabola by changing opacity from a clear translucent state to a cloudy white and, later on, amber hue.
This transition of color within a trichome head represents its peak ripeness and farmers typically use this as a sign to harvest, as it’s the point when the trichome has reached full maturation and will begin to degrade from this point forward. It is important to understand that not all strains of cannabis are the same and some trichomes will display maturation differently. Nevertheless, trichome coloration remains the standard for determining a harvest time for most strains.
Whether alive on a vine or harvested, trichomes are incredibly volatile and risk destruction and/or degradation at the hands of many catalysts, including but not limited to:
- Physical contact or agitation
- Heat
- Light
- Oxygen
- Time
Not only do the trichomes themselves risk damage when exposed to these elements, but the essential oils within them risk degradation. There are ways to dramatically slow degradation of trichomes by carefully handling cannabis flowers both during propagation and post harvest. By limiting physical contact and agitation to the flowers themselves, trichomes may be preserved on the plant for longer periods of time. Proper trimming, drying, and curing techniques can help keep trichomes viable for longer, which in turn will preserve the cannabinoids and terpenoids contained within.
How cannabinoids are created in trichomes
Cannabinoids are produced within the trichome cells through biosynthesis, in which enzymes catalyze a series of chemical reactions to produce complex molecules from simple (smaller) molecules.
The three basic steps for cannabinoid biosynthesis are binding, prenylation, and cyclization. Molecules called enzymes bind to one or two small molecules called substrates, attach the substrates to each other, then pass the transformed substrate down an assembly line to another enzyme that processes it, cycling the small molecule through further sequential changes.