Anatomy of a Cannabis Plant

Cannabis. Bud. Sensimillia. It goes by many names but what actually makes up a cannabis plant? While the distinctive fan leaves have become the iconic symbol of cannabis, it’s the female flower buds that are harvested for their cannabinoid-rich content. Here, we take a look at the anatomy of a cannabis plant beyond buds and leaves and explain why each part is important.

Male and Female Plants

Just like most other herb plants, Cannabis sativa L is made up of roots, a stalk, leaves, and flowers. Plants are male or female, and occasionally both in the case of self-pollinating hermaphrodite plants. Male plants do not flower but instead have small pollen sacs near the base of their leaves to pollinate female plants. Unfertilized, and therefore seedless, female plants grow large resin coated buds, these are the cannabinoid-rich ones that are chosen for their potency. Growing plants from genetically-identical cuttings from a parent strain helps growers to ensure the sex and cannabinoid content of the plants.

female plants grow large resin coated buds, these are the cannabinoid-rich ones that are chosen for their potency

Roots and Stalk

Starting with a single taproot, the cannabis plants root zone grows underground into a fibrous mass that forms the vascular system to pump water and nutrients throughout the plant via the stalk. The stalk also acts as a support structure for the entire plant and is integral to the development of the flowering bud (the cola) as it grows.

Nodes and Leaves

The cannabis plant's distinctive symmetrical fan leaves grow out of nodes, which connect them to the main stalk. The leaves are responsible for photosynthesis, converting sunlight to energy, and act as solar panels to fuel the plant. Fan leaves are low in cannabinoids and generally not harvested for recreational or medicinal use, despite being the ubiquitous symbol for cannabis. Indica plants have stubbier and thicker leaves than sativa plants, which grow taller and have thinner leaves (see last week’s blog for more information about the differences between the two).

The Cola

Nothing to do with a soft drink, the cannabis plants cola refers to the flowering site, or bud, of the plant. Where male plants have pollen sacs, female plants have a tightly packed collection of buds that grow at the top of the plant (the apical bud) and as smaller colas on lower stems.



Wispy white pistil ‘hairs’ are the first sign of buds growing from the calyx, which is the protective platform for the flower. The long ‘hairs’ of stigma are a sticky resin trap for pollen from birds, wind, and insects. Pistils start out white and gradually darken to an orangish brown -- you’ll notice this visually but it has limited effect on the taste or potency of the plant.

Bract and Calyx

Tiny ‘sugar leaves’, aka the bract, enclose and surround the calyx, which is a teardrop-shaped translucent layer that protects the plant ovules and would become an ovary if fertilization takes place. Some buds have tightly packed calyxes and others have a looser arrangement but they generally look like a tangled mess of fleshy leaves. Green bract leaves are covered in tiny resin crystals that look like sugar: these are trichomes and this is where the bud has the highest concentration of cannabinoids.

Rich in terpenes (fragrant oils), CBD, and THC, the trichomes are the most prized part of the bud.


Trichomes are where the magic happens. If you take a look at any cannabis bud, you’ll see a carpet of tiny resin ‘crystals’ that cover it: trichomes are the name of the glands that secrete this resin onto the bud. Sparkling like diamonds, and just as precious, the trichomes bloom as a forest all over the bud, most noticeably as microscopic mushroom-shaped stalks on the calyxes.

Bitter to the taste, this thick resinous coat is designed to protect the plant against predators and the natural elements. Rich in terpenes (fragrant oils) and cannabinoids like CBD and THC, the trichomes are the most prized part of the bud and are where hashish and other concentrates are extracted from.


Trichomes come in three different types and sizes from the smallest bulbous to the larger capitate-sessile, and the distinctive capitate-stalked, which can be seen with the naked eye. It’s thought that all types act as little factories that pump out cannabinoids and terpenes.

Organelles called vacuoles and plastids, which are found in the cannabis flower's resin gland cells, produce and store the terpenes. There they combine with UV light from the sun to create cannabinoids such as THC and CBD, making light an essential part of the growing process.


A large number of visible trichomes doesn’t necessarily mean that the cannabis plant will be highly potent in THC, CBD or specific terpenes but it is a good sign of cannabinoid content in general and is essential to the production of them.

Next time you have a cannabis bud in your hand, take a closer look at the amazing ecosystem that can be found there or find out more about the main two types of cannabis plants on our Indica vs Sativa blog.

Tantalus Labs

Tantalus Labs

Tantalus Labs is leading Sungrown, BC cannabis. We created SunLab¹, a facility using natural inputs to grow elite cannabis products.