When we look closely at a cannabis plant, there is one detail that usually catches the eye: that kind of tiny crystals that cover the flowers and that, when reflected by light, look like a shiny and sticky layer. Those microscopic dots are the trichomes. You may have heard them referred to as “the resin” or “the powder” that then gives life to extracts and concentrates, but in reality their history is much more interesting. In this article, we’ll look at all the natural secrets behind these tiny but powerful structures in plants.
What Are Trichomes and Where Do They Appear in Cannabis?
Trichomes are microscopic extensions of the plant’s skin, as if they were small hairs that grow from the epidermis. Andre et al. (2016) describe them as epidermal prolongations that can be of two types: glandular and non-glandular. The difference is that the former produce and store chemical compounds of great interest, while the latter function more as a physical barrier. When we talk about hemp and other types of cannabis plant, the most striking thing is the glandular trichomes, because they concentrate the production of cannabinoids and terpenes, that is, the substances responsible for the effects and aromas that make this plant so special.
Glandular trichomes: those that concentrate the resin
Within the world of glandular trichomes we find several forms. For years, there was talk of three main types: bulbous, capitate-sessile and capitate-pedunculated. Andre et al. (2016) took up this classic classification and showed it as the basis for understanding how they are distributed.
Bulbous trichomes
They are the smallest and most discreet. They barely measure a few tens of microns and usually go unnoticed by the human eye, even with a magnifying glass. They are embedded in the epidermis, almost without protruding, and their ability to produce resin is limited. You could imagine them as the first microscopic defenses, present on many surfaces of the plant but without a significant contribution to the concentration of cannabinoids. Still, they are part of the overall trichome landscape and play their role in basic protection.
Capitate-sessile trichomes
These trichomes have a globose head sitting directly on the epidermis or with a very short, almost imperceptible peduncle. Andre et al. (2016) explain that cannabinoid-rich resin also accumulates in their heads, although in smaller quantities than in pedunculated ones. Visually they are a little more noticeable than bulbous ones, but still small.
Capitate-pedunculated trichomes
They are the largest and most showy trichomes, with a well-defined peduncle that supports a globose head filled with resin. When you look at photos of cannabis covered in a shiny coating, most of that “frost” is pedunculated. Andre et al. (2016) pointed out that they concentrate the highest amount of THCA, while Tanney et al. (2021) showed that in mature flowers they have between 12 and 16 cells responsible for secreting components, which gives them a higher productive capacity than the other types. These trichomes are truly responsible for the potency and aromatic profile of the flower.
What the Latest Science Reveals About Glandular Trichomes
Over time, science has revised this classification. Tanney et al. (2021) showed that what was previously called “sessile trichome” in flowers could actually be a previous state of a pedunculate. They found that true sessile leaves have exactly eight cells in the secretory disc, while mature pedunculates in flowers have between twelve and sixteen. Those that looked like sessile in immature flowers are not a different type, but precursors of the trichomes that produce the most cannabinoids. This observation is key because it not only corrects the classification, but also allows a better understanding of the maturity of the plant and the biosynthetic capacity of each trichome. In the end, flowering pedunculates are the ones that produce the most resin and, therefore, the most sought after when you want to maximize the quality of cannabis.
Non-glandular trichomes
Although glandular trichomes attract attention, they are not the only ones that exist in plants. There are also non-glandular trichomes, which serve very different functions. Andre et al. (2016) describe them as structures that do not produce or store resin, but serve as a mechanical defense. These include unicellular carbohydrates, which are simple extensions, and cystolytic cells, which usually contain calcium carbonate deposits and are more rigid. These trichomes act as a barrier against insects, making it difficult for some animals to feed on the plant, and helping to reduce water loss. While they don’t influence the potency or aroma of cannabis, they’re just as important from a plant survival standpoint.
The interior of the trichome: what happens in the resinous cavity
One of the most amazing things about glandular trichomes is what happens inside that little transparent bubble you see on the flower. Imagine that the plant has a natural mini laboratory in there. In this space, the most valuable compounds are mixed and accumulated: cannabinoids, such as THCA or CBDA, and the terpenes that give it aroma. The cells surrounding the head of the trichome are responsible for making these substances and then releasing them into the internal cavity, where they are trapped as a sticky resin. As the flower matures, this resin changes its appearance: first it looks transparent, then it acquires a milky tone and finally it turns amber. To the trained eye, these changes are like a natural clock that marks the right time to harvest.
Colours as signs of ripening
Surely you have heard that trichomes are looked at with a magnifying glass to know when to harvest. This practice has scientific backing. Both Andre et al. (2016) and Tanney et al. (2021) described how the cavity contents go from transparent in early stages, to milky when at the point of maximum secretion, and finally to amber or brown when it begins to age. For the grower, these colours are very clear signs: harvesting at the milky time is usually associated with greater potency of aromas and effects, while waiting for amber can offer a more relaxing profile. Thus, the trichomes become a visual guide to obtain flowers and buds tailored to the grower.
What are trichomes for?
Trichomes don’t appear just so that we can enjoy the resin; The plant produces them as a natural defense mechanism. On the one hand, the resin they generate is sticky and serves to trap small insects. On the other hand, within that same resin there are compounds that are unpleasant or even toxic to those who try to feed on the plant. Research such as that of Andre et al. (2016) explains that this mixture of cannabinoids and sticky aromas helps to keep intruders away.
But the protection does not stop there. According to Tanney et al. (2021), there are also signs that trichomes help the plant withstand intense sunlight, especially ultraviolet radiation. In other words, they are like an extra layer of protection against harsh environmental conditions.
Now, if we move from the function of defense to human interest, we understand why trichomes are so important in cannabis cultivation. They are the ones who concentrate the resin where the cannabinoids and terpenes that define the characteristics of each variety are. Among all, mature pedunculated trichomes are the ones that produce the most and make the difference between an ordinary flower and a high-quality flower. Learning to recognize them and observe their development is one of the keys to making better decisions when growing or harvesting.
Conclusion on Trichomes
When reviewing each of these types, it is clear that not all trichomes provide the same thing. The bulbous ones play a more discreet role, the sessile ones represent an intermediate and defensive stage, and the pedunculates are the real resin factories where most of the cannabinoids and terpenes are concentrated. That’s why, when you look at CBD flowers covered in shiny crystals, you’re actually seeing the silent work of the pedunculated trichomes, responsible for those flowers retaining their characteristic potency and aroma. Understanding these differences not only enriches the view of growers, but also guides those who decide to buy CBD, because they will know how to better value the quality of a flower through the density and ripening of its trichomes. And if you want to buy the best CBD at the best price, don’t forget to stop by our Maionais CBD store.
References
Andre, C. M., Hausman, J. F., & Guerriero, G. (2016). Cannabis sativa: The Plant of the Thousand and One Molecules. Frontiers in plant science, 7, 19. https://doi.org/10.3389/fpls.2016.00019
Tanney, C. A. S., Backer, R., Geitmann, A., & Smith, D. L. (2021). Cannabis Glandular Trichomes: A Cellular Metabolite Factory. Frontiers in plant science, 12, 721986. https://doi.org/10.3389/fpls.2021.721986
