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What Are Trichomes and How Do They Affect Medical Marijuana?

Those tiny, shiny bulbs that appear on your medical marijuana contain most of the plant’s cannabinoids and other beneficial compounds.

Take a close look at medical marijuana plants and you’ll notice shiny and sticky crystals that blanket the plant’s leaves and buds. These are trichomes — tiny microscopic outgrowths that contain most of the cannabinoids, terpenes, and flavonoids that make your medical marijuana therapeutically beneficial.

Here we take a look at trichomes, their purpose, and how they play a key role in the effects of medical marijuana.

What are Trichomes?

Trichomes are small resin glands found on marijuana flowers, leaves, and in lower numbers, stalks. Originating from the Greek word “Tríchōma,” meaning “growth of hair,” trichomes under a magnifying glass look like tiny hairs with a round, bulbous “head” at their tips. To the naked eye, these resin glands, ranging in width from 10 to 100 micrometers, look like shiny, sticky crystals.

Trichomes begin to appear on marijuana as soon as the plants enter their flowering stage, toward the end of the lifecycle and just before the buds are ready for harvest. As the plant’s buds begin to appear, trichomes also start to form along the stalk and the buds. Growers need to be careful when handling marijuana plants during the flowering stage, as trichomes are volatile and can be degraded by physical contact, heat, light, and oxygen.

While trichomes offer multiple benefits to the marijuana plant, to medical marijuana consumers they’re primarily appreciated because they hold the compounds that are responsible for cannabis’ beneficial effects.

Why are the Function of Trichomes?

Trichomes aren’t limited to marijuana plants. Rather, the production of trichomes can be observed in many species of plants, taking on various physical forms. They help keep plants safe, healthy, and productive.

On cannabis, trichomes serve as defenders against insects, animals, and other non-living environmental variables that may harm the plant. When female marijuana plants begin producing buds, they become especially vulnerable to pests. Ants, caterpillars, and moths are just some of the bugs that may ruin your plant’s buds.

With their strong aroma and bitter taste, trichomes help deter animals and bugs. They also help protect the plants from potentially harmful UV rays and damaging winds.

If you’re growing your own marijuana, trichomes can help you know when your flowers are ready for harvest. When trichomes are clear, the plants are not yet fully mature. Once the trichome stalks appear cloudy or a red or amber color, depending on the strain, you can expect that the flowers have developed or are close to developing an ideal cannabinoid profile.

marijuana trichomes

Why are Trichomes Important to Medical Marijuana?

While the entire marijuana plant contains cannabinoids, it’s within the plant’s trichomes that the beneficial compounds are most highly concentrated.

Compared to the rest of the marijuana plant, trichomes contain a much higher concentration of:

  • Cannabinoids
  • Terpenes
  • Flavonoids


Marijuana contains more than 100 so-far identified cannabinoids, including the well-known compounds tetrahydrocannabinol (THC), the psychoactive compound that elicits a euphoric effect, and cannabidiol (CBD). These cannabinoids interact with your body’s native endocannabinoid system, a regulatory network that keeps many of your functions in homeostasis.

Sharing a similar chemical makeup as the endocannabinoids that are synthesized by the body, cannabis-derived cannabinoids are able to interact with the endocannabinoid system’s cannabinoid receptors to stimulate the chemical reactions to produce natural beneficial effects.


Responsible for giving medical marijuana flowers their flavor and aromatic diversity, terpenes have also shown to work with cannabinoids to enhance their natural balancing properties in what’s called the “entourage effect.” Like cannabinoids, terpenes bind to receptors to stimulate wide-ranging effects, and alter the release of neurotransmitters like dopamine and serotonin.


Flavonoids are phytonutrients that contribute to the plant’s color, taste, and smell. They also  work together with the other compounds to encourage a wide variety of health benefits. Flavonoids unique to cannabis are called “cannaflavins,” and research has already discovered that they offer some promising properties.

What are the Different Types of Trichomes?

On the marijuana plant, there are three types of trichomes:

  • Bulbous
  • Capitate-sessile
  • Capitate-stalked

Bulbous trichomes are the smallest of the three types, nearly invisible to the naked eye. They appear on the surface of the entire plant, and are as small as 10-15 micrometers. While bulbous trichomes do contain cannabinoids and other compounds, their tiny size limits their capacity.

Slightly larger and more common, capitate-sessile trichomes contain a small stalk and head that is more abundant in cannabinoids compared to the bulbous type.

Ranging anywhere between 50-100 micrometers wide, capitate-stalked trichomes are the largest variety of the resin glands, and in general the type that you’ll likely notice when looking at your medical marijuana plants. They feature a prominent stalk and large gland head that serves as the focal point for most of the cannabinoids and other beneficial compounds.

Trichomes: The Source of Kief and Hash

Medical marijuana users interested in increasing their cannabinoid intake can harvest trichomes and use them to produce the kief or hash. By containing only trichome heads, the two concentrates offer the highest potency of nearly all marijuana products.

Kief is the accumulation of trichomes in the form of a shimmery powder. Typically, a three-chamber herb grinder is used to separate the kief from the flower, producing a highly-potent concentrate that can be inhaled by smoking or vaping, or added to foods and beverages.

Hash is similar to kief, except that the trichomes are pressed into a solid mass. Most commonly made by separating the flower’s trichomes from the plant by hand or dry-sifting with a screen, hash can be inhaled via smoking, vaping, or dabbing, or infused into marijuana edibles.

trichomes hash

Learn More about Medical Marijuana

Marijuana is now legal in some capacity in more than half of U.S. states, with 29 states permitting the use of marijuana for medical purposes and eight legalizing recreational use. As a result, more people are interested in learning how to grow and harvest their own marijuana.

You can learn even more about growing and handling marijuana by visiting our Cannabis 101 page.

  • December 17, 2017
  • Eve Ripley