The genus Cannabis belongs to the family Cannabaceae. Carl Linnaeus described Cannabis sativa in 1753; Jean-Baptiste Lamarck described Cannabis indica in 1785 based on specimens from the Indian subcontinent, noting differences in leaf morphology and growth habit. A third designation, Cannabis ruderalis (Janischewsky, 1924), is sometimes recognised for low-THC, auto-flowering varieties originating in Central Asia and Eastern Europe. Whether these constitute distinct species, subspecies, or ecotypes of a single polymorphic species remains an active area of taxonomic debate, with many botanists preferring a monotypic classification under Cannabis sativa L.
Morphologically, plants historically labelled sativa are described as tall (sometimes exceeding three metres), with narrow, elongated leaflets and a longer photoperiod-dependent flowering cycle. Plants labelled indica are typically shorter and bushier, with broader leaflets and a comparatively shorter flowering period. These distinctions reflect adaptation to differing climates: broadly, equatorial and temperate zones for sativa types, and the Hindu Kush mountain region for indica types. Selective breeding and widespread hybridisation across centuries mean that most cultivated varieties today are genetically heterogeneous, making strict morphological assignment unreliable.
In contemporary phytochemistry, the sativa/indica binary is frequently , and loosely , used in commercial contexts to indicate expected cannabinoid and terpene ratios, but this usage is not supported by a consistent or verified correlation in the peer-reviewed literature. A 2015 study in PLOS ONE (Sawler et al.) applying genomic analysis to hemp and drug-type varieties found that the genetic structure of Cannabis populations did not map neatly onto the folk-taxonomic sativa/indica distinction. Terpene composition varies substantially between cultivars regardless of the label applied, and cannabinoid concentrations (THC, CBD, CBG, and others) are determined by genetics, cultivation conditions, and processing , not by species designation alone.
In Australia, all Cannabis species and cultivars are regulated under the Narcotic Drugs Act 1967 (Cth) and scheduled under the Poisons Standard (the Standard for the Uniform Scheduling of Medicines and Poisons). Tetrahydrocannabinol (THC) is listed as a Schedule 8 controlled medicine in approved formulations; cannabis plant material remains Schedule 9 (prohibited) outside of licenced cultivation under the Office of Drug Control framework administered by the TGA and the Department of Health and Aged Care. Botanical classification does not alter scheduling status.
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