Everyone who falls in love with cannabis eventually comes around to learning about trichomes. Let us learn more about these glands present in the cannabis plant and having very specific functions.

Trichomes are epidermal bumps found on plants

Trichomes are small outgrowths that look like fine hairs or scales on many plants, algae, and lichen, and they serve several biological functions. In cannabis, trichomes are sometimes called "kief" or frosting, and they are the sticky, aromatic resin glands that stay on your fingers after you handle cannabis flowers.

"Trichome" comes from the Greek word for "hair" and to the naked eye, they are shiny, crystalline hairs that coat the surface of mature cannabis flowers. With a hand-held microscope, you can usually see that each trichome has a distinctive, mushroom-like shape. This blanket of trichomes serves several purposes, including protection from ultraviolet rays, wind, humidity, pests, and herbivores, but in cannabis, their importance lies in the mix of desirable compounds they produce.

Trichomes have the highest amount of cannabinoids

These glands are the last part of the cannabis flowers to develop, and they have their own growth cycle that begins once the plant is mature. They appear on the surface of flowers as clear or slightly amber in color, then turn cloudy and opaque when the chemical compound levels are at their highest. This change in color serves as a signal to farmers as the best time to harvest the plants. Trichomes are what we extract from cannabis flowers when making infusions and concentrates because it is within these hair-like glands (particularly the mushroom "cap" at the top) that the highest amounts of cannabinoids, terpenes, and flavonoids are produced and stored – not the green plant tissue as scientists used to believe.

This better understanding of trichomes on cannabis flowers has been key to developing smokeless consumption methods and purer, more potent concentrates. You can also collect "kief" with a three-chambered grinder, which separates some of the dry, powdery trichomes from dried flowers.
With your new-found knowledge about trichomes, you should get in the habit of examining how they look on each batch of cannabis you grow or buy. However, we can never assume that just because a plant is covered in a thick blanket of trichomes that it will deliver one effect or another because each strain produces its own unique blend of chemical compounds.

There are three major types of trichomes

There are three main types of trichomes, including stinging hairs, glandular hairs, and scale or Peltate hair.

Stinging hairs

Stinging hairs are one of the most interesting types of trichomes. They contain a poisonous liquid and consist of a basal bulb-like portion from which a stiff structure is given out. Stinging hairs are defined as the trichomes that have the ability to inject a chemical substance through the skin of an animal causing irritation or pain. Plants with stinging hairs have the same structure – a single elongated cell with a brittle tip supported by a solid base. When the body of an animal or human being comes in contact with some force, the tip is broken off. As this happens, the exposed sharp point penetrates the skin of the animal or person with the fluid being transferred from the basal knob of the hair to the body. The stinging fluid consists of histamine, acetylcholine, and serotonin. Plants bearing stinging trichomes are known as ‘nettles', and usually occur in the families Urticaceae, Euphorbiaceae, Loasaceae and Hydrophyllaceae

Glandular hairs

Many plants contain glandular trichomes. They are specialized hairs found on the surface of about 30% of all vascular plants. They are responsible for a wide portion of plants' chemistry. Glandular trichomes are frequently present in the Lamiaceae. They are responsible for secreting essential oils and vary in the number of secretory cells, the length of the stalk-cell and the amount of oil secreted. The storage compartment of glandular trichomes is found on the tip of the hair and is part of the glandular cells, which are metabolically active. Glandular trichomes are usually multicellular and consist of differentiated basal, stalk and apical cells.

Peltate hairs

Also known as scale, peltate trichomes consists of a discoid plate of cells, often borne on a stalk. The peltate is a flat circular structure having the stem or support attached near the center of the lower surface. The shield that the peltate contains is made up of a considerable number of ray cells which usually have thickened walls.

Cannabis contains three different trichomes

If you've looked carefully at a cannabis plant, you must have noticed the tiny little crystals that cover its leaves and buds. They are shiny, sticky and carry the most amazing aromas. The resinous glands found on the cannabis plants are the trichomes. They function as a defense mechanism. When the female cannabis plants begin to produce flowers in the wild, they become vulnerable to insects, animals, and harmful Ultra Violet rays. Fortunately, trichomes serve as a deterrent. They prevent animals and insects from approaching thanks to their bitter taste and strong aromas.

Trichomes also prevent damaging winds and fungal growth. In addition, trichomes are the ‘sunscreen' of growing marijuana plants.
Surprisingly, there are three trichomes with varying physical structures in cannabis plants. Even though the trichomes differ in size and shape, they produce the same cannabinoids, terpenes and other chemical compounds that make cannabis unique. The three types of trichomes found in cannabis plants include bulbous, capitate-sessile and capitate-stalked.

Bulbous trichomes

The smallest of the three trichomes, bulbous is approximately 15 to 30 micrometers. Bulbous is barely visible to the naked eye. Bulbous trichomes are formed sparsely across the surface of the plant and each one is made up of a few cells. The trichomes consist of a secretory head that contains one or two-celled base layer adjacent to the epidermis. Bulbous is present on most serial epidermal surfaces of both pistillate and staminate plants.

Capitate-Sessile trichomes

Capitate-sessile trichomes are medium-sized. They cover cannabis plants more densely than bulbous trichomes. Being around 25 to 100 micrometers, capitate-sessile glands have a globular-shaped head and consist of a single-cell stalk. The rounded gland on top of this trichome consists of 8 to 16 cells that group to form a convex rosette. The cells secrete cannabinoids and other compounds that accumulate between the rosette and its outer membrane.

Capitate-Stalked trichomes

Capitate-stalked is the largest trichome found on cannabis plant. The trichomes appear during the flowering phase and form the protective outer layer of small leaves that surround new buds. Capitate-stalked glands consist of a tier of secretory disc cells subtending a large non-cellular secretory cavity. These types of trichomes are the elements that cannabis growers look for when harvesting a crop because they produce the highest concentrations of cannabis unique chemical compounds. Male plants have smaller and less concentrated capitate-stalked glands than female plants.

Trichomes act as an indicator for harvesting time

Trichomes allow cannabis growers to know the state of maturity of female cannabis plants in the final stages of growth. Different strains of cannabis indicate their readiness for harvest in different ways. On the one hand, if the trichomes are cloudy or milky in color during harvest, the cannabinoid profile will deliver a more energetic and sativa-like high. On the other hand, if they are amber or brown in color, the cannabinoids are more likely to deliver a more relaxed body high. However, it should be noted that some strains do no become amber when it's time for harvest. Therefore, cannabis growers are usually recommended not to rely too heavily on the appearance of trichomes to determine the harvest schedule.

Cannabis extracts are more potent than standard cannabis buds

Also known as cannabis concentrates, cannabis extracts prove to be more effective and potent than standard cannabis herbs. The simple reason behind this is that in the extracts, there are more of the desired compounds. In fact, the main goal of extraction is to reduce chemicals which could be potentially harmful. As compared to fresh herb, concentrates contain up to 99% of pure THC and CBD. A cannabis concentrate is reminiscent of the cannabis strain it was extracted from. The smell, taste, and effects are expanded thanks to a larger concentration by weight. The different cannabis concentrates include Kief, Dry Sieve, Hash, Butane Hash Oil (BHO), Rick Simpson Oil (RSO) and Rosin.

Kief consists of trichomes broken away from the dried plant material and it is considered as a lower-quality extract. It contains around 20 to 60 percent of THC. Dry sieve is a refined version of kief that has been passed through a series of screens. Hash is made by ice water extraction. The trichome heads are isolated from the stalks and plant matter that carry no medicinal value. BHO is made using butane. With this extraction method, THC content can range from 80 to 90%. Rick Simpson oil is also known as cannabis oil or hemp oil. It is usually used to treat cancer and other diseases. Rosin is also a medical cannabis that is obtained by adding pressure and heat. This technique is simple and quick. Quality solventless hash is created in a matter of seconds.

The type of plant you use depends on your objectives. For example, if you want to have high CBD extract with no THC, you need to use hemp or CBD-rich cannabis strains with low THC content. To avoid pesticides, fertilizers or other related chemicals, it is imperative to use only organically-grown cannabis for extraction.