Cannabis Plant Anatomy: Every Part of the Plant, Explained

The main parts of a cannabis plant are the roots, stem and nodes, fan leaves, colas, bracts and calyxes, pistils and trichomes, and each one has a specific job. Every part of the plant has a role and a reason for being there. 

When it comes to cannabis anatomy, the flower usually gets most of the attention, since that's the part people actually consume. But every part of the plant plays a vital role in bringing those flowers to life.

Cannabis anatomy: what are the most important parts of the plant?

Cola:

The main cola, or apical bud, is the part of a cannabis plant that forms at the very top of the plant. You'll also find smaller colas at the bud sites along the lower branches.

Stigma and pistil:

The pistil houses the reproductive organs of a cannabis flower. The stigmas are the bright, hair-like strands growing from the pistil. Their job is to catch pollen from male cannabis flowers. Stigmas change color as the plant matures, starting out white and darkening over time to yellow, orange, brown and red. They play a big part in reproduction, but they have little effect on the flavor or potency of the flower.

Bract and calyx:

Cannabis bracts house the reproductive parts of a female cannabis plant. They look like small, teardrop-shaped green leaves, and they're covered in resin glands that produce higher concentrations of cannabinoids than any other part of the plant. The calyx is a translucent layer covering the ovule at the base of the flower and usually isn't visible, since it's tucked inside the bracts.

Trichome:

No rundown of flower anatomy is complete without trichomes: they're tiny, but together they form the crystal-coated resin layer on cannabis buds. Secreted by translucent, mushroom-shaped glands on the stems, leaves and calyxes, this resin is what we call kief once it dries. Trichomes also protect the plant from the elements and from predators. They produce terpenes, the aromatic oils, along with cannabinoids like CBD and THC.

Seed:

The seed is one of the most important parts of the plant, because it's where everything begins. A healthy, mature cannabis seed is nicely rounded, with one flat end and one pointed end, and has a hard, tough shell that keeps it from getting crushed easily. Inside the seed is the plant embryo, which holds everything the plant needs to start a new life once it's planted and cared for.

Roots:

The roots are the foundation of a cannabis plant. The root system has three main jobs: anchoring the plant in the growing medium, supplying water and nutrients for growth, and storing the starches and sugars made through photosynthesis. The taproot is the first thing to emerge from a germinated cannabis seed; it grows down into the soil looking for nutrients and moisture to help the plant grow. Once the taproot has stretched out, fibrous roots branch off to form an underground network.

Stem and nodes:

The stem is what keeps a cannabis plant upright and carries its weight. It also contains the vascular system that moves nutrients and moisture from the roots up to the leaves. The stem is divided by nodes, and seedlings grow opposite pairs of leaves and nodes at first, but once they start growing in an alternating pattern, that's a sign the plant is mature and ready to flower.

Leaves and petioles:

The cannabis leaf is shaped like an open hand, with three to 13 veined leaflets. Plants have both small leaves and big fan leaves. The leaflets attach to the branch or stem by a leaf stalk called a petiole. Petioles vary in color and length depending on the strain.

Flower anatomy: female or male cannabis?

There are male and female cannabis plants, plus some that are a mix of both sexes. Cannabis is a dioecious plant, meaning male and female organs grow on separate plants.

Males fertilize female plants to kick off seed production. The resin-producing flowers of the female cannabis plant are what get trimmed down into buds, and those flowers are what we consume. Mixed, or hermaphrodite, plants carry both male and female organs, which lets them pollinate themselves during flowering. Growers generally see them as a nuisance, because self-pollination ruins seedless plants that would otherwise produce very potent flowers.

Male cannabis plants develop stamens with anthers, which produce the pollen that will fertilize the female (pistillate) plants, the ones that go on to make seeds. Male pollen is stored in small oval sacs that cluster at the nodes and split open when ripe, revealing five stamens that release the pollen. Once mature, males usually die off soon. They produce very little in the way of cannabinoids and terpenes.

Female cannabis, on the other hand, is made up of clusters of bracts, which growers often call calyxes. These bracts hold the ovary and the pistil or stigma, which acts as the pollen catcher. Once pollen touches the stigma, it travels down to the ovary, where fertilization happens and a seed forms, filling the whole bract as it matures. The pistils wither once they've done their job (and also if they never get the chance). Seeds form about 4 to 6 weeks after fertilization.

 

Keep reading: