What Are Trichomes?
Trichomes are the resin glands that grow all over the outside of the cannabis plant. Trichomes appear as a shiny, sugar, crystal or hair-like structure to the naked eye. Growing on the outside of the cannabis plant, trichomes are “waxy sheathes” that contain the chemical compounds, cannabinoids, flavinoids and terpenes (scent and flavor). These glistening mushroom-like structures will look familiar to most cannabis flower consumers. Trichomes are also found in many other plants, not just cannabis.
Chemically, trichomes are where all of the magic happens. Without trichomes cannabis would not have a scent, taste or effect. The cannabinoid CBG is produced in the trichomes and then is converted to other cannabinoids (CBD, THC, etc.) as the plant matures, giving consumers a varying spectrum of effects based on the cannabinoid profiles found in the trichomes.
Trichomes can be observed under a microscope, displaying the “clarity” of the trichomes. When the plant is immature, the trichomes appear clear in color. When the plant is at mid-maturity, the trichomes appear cloudy due to the resins and chemicals slowing production. When the plant is fully mature, the resins and chemical production slows, causing the cannabinoids to oxidize making the trichomes appear amber. Amber trichomes are reported to have more of a sedative effect. (Typically, cultivators look for a 5-15% “amber” rate before harvesting)
In this post we will explore what trichomes are and what you should be looking for to ensure that you getting high quality, trichome-rich cannabis flower.
The Purpose of Trichomes
Trichomes produce cannabinoids and terpenes mainly as a form of defense and protection. These glands secrete terpenes and cannabinoids that provide pest and disease protection for the plant. Terpenes can also help the plant maintain proper humidity levels so that the plant doesn't dry out. Animals that eat cannabis plants may be deterred from eating cannabis due to the psychoactive effects of the cannabinoids and the scents that the trichomes produce. Cannabis grows in many different biomes, some of them within very high elevations. Trichomes help to protect the plant from harmful UV radiation coming from the sun as well. It just so happens that humans humans enjoy and can benefit from the complex chemicals that these wonderful resin glands provide.
Trichome Physical Appearance - Surface Trichome Coverage
Trichome coverage is the amount of glandular trichomes visible on the surface of the cannabis flower using the naked eye. Cannabis plants produce around 6 types of trichomes. However, when inspecting cannabis using the naked eye we are concerned with one specific types of trichome: the capitate trichome. Capitate trichomes can be further broken down into two types: capitate sessile and capitate stalked. Capitate sessile appear very short and stout, without the presnce of a long stalk. Capitate stalked trichomes on the otherhand, have a long, extended stalk creating a mushroom-like appearance with the large trichome head sitting on top of the stalk.
On a lesser impact to overall quality, the cyctolithic trichome is an important producer of “shine” as the light catches them. These pointed, thin, “bear claw” shaped trichomes sparkle is visible using the naked eye with proper lighting and angle. More aesthetic than functional, but definitely cool nonetheless.
When inspecting flower for trichome coverage, we are looking for overall coverage and density. Trichome density can be defined as how close the trichomes are to one another. Generally it is favorable to have a dense, closely packed trichome coverage pattern on the outside of the bud. Heavy trichome coverage indicates a higher amount of cannabinoids, flavinoids, terpenoids, favorable genetics and growing conditions.
Trichome Appearance - Microscopic Trichome Coverage
Since trichomes can tell us quite a bit about how the end flower product has been grown, processed and handled it is important to inspect the trichomes underneath a microscope to get a closer view (if you have access to one). We use a microscope to evaluate the ratio of the types of trichomes present in our flower (we look for the 6 different trichomes and how many exist). On a favorable example of cannabis flower you want to see a higher ratio of trichomes (capitate and bulbous) than any of the other types of trichomes.
Microscopic Trichome Integrity
Trichomes contain all of the good stuff, but sadly they are the most fragile part of the cannabis flower. While under the microscope, the physical development of the trichomes must be inspected. During this step, you should be mostly looking at capitate stalked trichomes. Start by viewing all trichomes under the microscope, within your view in the scope, check to see if the stalks of the trichomes are fully developed. Are they misformed? Short? Bent?
Next, we check the heads of the trichomes that sit on top of the stalks. On many samples you will see missing trichome heads. These look like a stalk with no top. (Think of a mushroom without a cap) These could be missing for a multitude of reasons, most notably poor handling, poor growing conditions (usually lack of UV light) and poor genetics. General rule of thumb, the less trichome heads there are, the less potent and lower quality the end product is.
Microscopic Trichome Maturity
Near the end of the cannabis plant growth cycle, cultivators will start to pay attention to the color of the trichome head itself. Inspecting the trichome head’s color can tell us how mature the trichome head is. These trichomes will be either clear (transparent), cloudy or amber colored based on the capacity of the resins and chemicals contained in the trichome. Clear trichomes indicate immaturity, low amounts of cannabinoids, terpenes and flavinoids. Cloudy trichomes indicate ripe trichomes with peak amounts of cannabinoids, terpenes and flavinoids. Amber trichomes indicate that some oxidation has started to take place within the trichome. (THC converting to CBN) Cultivators prefer harvesting their flower when trichome maturity reaches a 70/30 ratio. (70% Cloudy / 30% Amber) The trichome maturity can change the feel of the flower, and some cultivators may play around with how early or late they harvest to change the effects of the final product. Just keep in mind that all trichomes mature at different rates, so there is no sure fire way to predict the exact maturity of thousands of trichomes contained on a single calyx.
Trichomes = Quality
In summary, the trichome is one of, if not the most important factor in quality cannabis. Trichomes store all of the elements that make up quality, potent and appealing flower. With your naked eye alone, you can identify preferred trichome coverage, structure and quality. With a relatively inexpensive microscope or jewelers loupe, you can dig into the flower and observe the trichomes up close. With this information and a few tools you can now evaluate cannabis flower (and it's trichomes) at the dispensary and at home before you purchase or consume it.