Taxonomic Classification of Cannabis sativa L.: from biology to cultural and medicinal relevance

Probably during elementary school, in Biology class, you heard about Formal Taxonomic Classification. If you don't remember, you at least recognize terms like "Domain", "Kingdom", "Phylum", "Class", "Order", "Family", "Genus", and "Species", which represent the hierarchical levels of life organization. Refreshed your memory?

Now let's understand how this system organizes biodiversity — and, especially, how it applies to a plant well known to Sechat Portal readers: Cannabis sativa L. The module two of the Extension Course in Endocannabinology, the result of the partnership between UFSC and Dalla Instituto, delves into the main aspects of medicinal cannabis and offers material with essential information for healthcare professionals. Here are some highlighted points: 

What is taxonomic classification

The so-called formal taxonomy, or systematic, is a method created to group living organisms into categories that range from broad to specific. This structure was organized by Carl Linnaeus in the 18th century and still serves as the basis for scientific nomenclature.

Simplified, it functions like an inverted pyramid: at the top is the Domain, which encompasses virtually all life on Earth, and at the base is the Species, the most restricted and individualized level. The further down the hierarchy, the fewer organisms fit into the group, but the closer their relationship.

This method is essential for identifying and naming living beings, as well as highlighting their relationships and evolution.

Where does Cannabis sativa L. fit in

Within this structure, Cannabis sativa L. belongs to the Domain Eukarya (organisms with complex cells), the Kingdom Plantae, and the Family Cannabaceae, which also includes the genus Humulus — the same as hops, used in beer production.

Currently, the classification recognizes only one formal species: Cannabis sativa L. (the "L." refers to Linnaeus, who described it). This species is divided into two main subspecies, each with distinct botanical and chemical characteristics.

The first, Cannabis sativa subsp. sativa, also called "hemp", is mainly cultivated for fibers and produces little or no THC, generally below 0.3%. Its plants are tall, reaching 3 meters, with thin and long leaves, usually with nine leaflets. They are traditionally used in the textile industry. Its wild or ruderal form is called var. spontanea.

On the other hand, Cannabis sativa subsp. indica, popularly known as "indica", has higher THC concentrations. It is divided into two main varieties: var. indica, originating from southern India, with narrower leaves, whose wild form is var. himalayensis; and var. afghanica, domesticated in the Afghanistan and Pakistan region, with broader leaves and a ruderal form known as var. asperrima. 

The cultivated seeds of these varieties tend to be larger than the wild ones, varying in color between darker (indica) or lighter (afghanica).

Over time, crosses between these varieties have given rise to numerous hybrids. A classic example is the Skunk #1 cultivar, created in the 1980s, which influenced various modern lineages.

The popularization of Cannabis sativa L. has led to some confusion in scientific terminology. Terms like "ruderalis" or "kafiristanica" have been used as if they were different species, but are now considered synonyms of already described varieties. Another common mistake is calling any plant with a narrow phenotype "sativa" and those with broad leaves "indica".

In practice, both belong to the same species, but different subspecies and varieties. For most purposes — scientific, medicinal, or agricultural — the most accurate reference is the cultivar (stable hybrid), and not just the generic term "sativa" or "indica".

History, uses, and modern science

Ethnobotany shows that Cannabis has accompanied humanity for millennia, in uses ranging from fiber production and edible seeds to ritual and medicinal consumption. Ethnopharmacology investigates traditional knowledge about the therapeutic use of the plant.

Even after decades of prohibition, Cannabis has become one of the most studied species in the world. In the 1960s, Israeli chemist Raphael Mechoulam isolated and described THC and CBD, as well as proposed the Entourage Effect. In the 1980s, Brazilian researcher Elisaldo Carlini demonstrated the efficacy of CBD against seizures, paving the way for its use in epilepsy.

Today, studies indicate that over 60% of anticancer drugs in clinical use have origins in natural products, reinforcing the importance of researching and using medicinal plants like Cannabis.