Cannabis sativa L. is the scientiﬁc name given to the cannabis or hemp plant in 1753 by the Swedish botanist Carolus Linnaeus. Since then, three main types have been identified:
Cannabis Sativa (Linnaéus 1753) or C. sativa L.
Cannabis Indica (Lamarck 1785) or C. indica Lam.
Cannabis Ruderalis (Janischevsky 1924) or C. ruderalis J.
Sativa, Indica and Ruderalis each have distinctive characteristics.
Probably the most common form of Cannabis worldwide and also the type with the most applications. As a botanical name, sativa simply means ‘sown’ and is applied to the cultivated or common form of many agricultural crops.
A typical Sativa is a tall plant, generally a lighter shade of green than the other types. Its leaves are made up of long, narrow blades. Female flowers are longer and more ‘feathery’ in appearance than those of an Indica.
In general, the foliage of a Sativa is sparser than that of the other varieties Sativas grow taller than the other types, gaining height all through their growing and flowering phases. This is due to the equatorial origin of Sativas. In the tropical regions the length of day does not change very much between seasons, so Sativas are adapted to accomplish both their growing and flowering in a fairly uniform photoperiod.
The female flowers of Sativa strains usually grow along the length of the stem and branches, instead of forming in clusters around the internodes, as with the other types. This flower formation is due to the Sativa tendency to grow and flower simultaneously. As a result, female Sativa flowers are usually less dense and weigh less than Indica flowers.
A pure Sativa often requires a combined grow/flower period of around six months to ripen completely. For this reason there is no such thing as a pure indoor Sativa strain. All Sativa strains that are viable for indoor growing have been hybridised with Indica strains to make them more compact and faster to flower.
Nearly all cannabis grown for industrial purposes is Sativa. As the tallest variety it produces the longest fibres and therefore has the widest range of industrial uses.
Indica varieties are generally agreed to have originated on the Asian subcontinent or possibly Afghanistan. Lamarck, the first European botanist to classify this type, received his samples from India and thus dubbed the plant ‘Indica’ in recognition of that fact.
A typical Indica is a much more compact, thick-stemmed plant, usually attaining a height of less than two metres. It is a darker shade of green, some examples appearing to have almost blue or green-black foliage. Its leaves are comprised of short, wide blades. An Indica tends to produce more side-branches and denser foliage than a Sativa, resulting in a wider, bushier plant. Female Indica flowers form in thick clusters around the internodes of the plant and usually weigh more than Sativa flowers of similar size.
The life cycle of an Indica is divided into two distinct photoperiods – growing and flowering. Growing occurs when the plant is in an environment of long days and short nights. Here, the plant devotes its energy to increasing in size. As days become shorter and nights longer, the plant receives the signal that winter is approaching and flowering is triggered. Here, upward and outward growth slows or stops as the plant devotes its energy to growing reproductive parts.
An Indica requires both a growing and flowering period in order to reach its full size.
Many Indicas are a rich source of the cannabinoids THC, CBD and CBN. While a Sativa may possess a higher proportion of THC relative to its other cannabinoids, an Indica will often contain significant levels of all three. When ingested, Indicas tend to produce more bodily effects than Sativas – effects such as enhancement of physical sensations, relaxation, dry mouth, red eyes. These Indica effects are often grouped together under the term ‘stoned’, as opposed to the ‘high’ imparted by Sativas. This is not to say that Indicas have no psychoactive effect, just that they also have noticeable effects on the body.
Indicas are cultivated almost exclusively for their medicinal and psychoactive properties. Lamarck, when classifying this type, commented that Indica’s “firm stem and thin bark make it incapable of furnishing similar fibres to the preceding species (C. sativa L.) of which so much use is made.”
The name ‘ruderalis’ comes from the German ruderal, a term for weeds growing by the roadside or on other fallow land.
Cannabis ruderalis is an uncultivated strain native to Russia and central Europe and is adapted to the harsher environments found in these locations. Whether seen as a variation on the single cannabis species or as a distinct species in itself, Ruderalis varieties are most likely descended from Indica varieties which, in turn, are probably descended from Sativas.
The differences between these three in their growing and reproductive patterns can be linked to the vastly different climates and environments encountered by the original tropical phenotype C. sativa L. as it colonised further and further north of the equator after the last ice age.
The most notable characteristic of the Ruderalis strain is its capacity to flower (and therefore reproduce) according to an individual plant’s age, independent of the photoperiod in which it is growing.
Since nearly all flowering plants take their cue to reproduce from the climatic factors indicative of season, the ability to begin this process based on changes in the plant rather than in its environment is known as ‘auto-flowering’.
A Ruderalis will begin flowering when it achieves a certain stage of maturity – normally after about seven weeks of growth, when it reaches its fifth to seventh internode. Once a Ruderalis has begun flowering, it continues to do so until other environmental factors (most notably winter) cause the plant to die. The other varieties may expire naturally once their reproduction has been accomplished, or may return to vegetative growth if given a long photoperiod.
Ruderalis’ adaptation to short, cool summers can be seen in other areas. Ruderalis has the ability to complete its life cycle – from being a seed to producing seeds – in just 10 weeks. Its seeds detach easily and can survive more than one season in frozen ground – until conditions are favourable enough to allow growth. The seeds can also survive their shells being cracked open when walked on by humans or animals. For some Ruderalis strains, this occurrence may even aid the germination of seeds.
A typical Ruderalis plant is very short in height, often between 10cm and 50cm at full maturity. It displays little or no branching and has wide, fat-bladed leaves, similar to those of an Indica. Once flowering begins, Ruderalis will gain even less height than an Indica.
Wild Ruderalis strains are nearly always high in CBD and low in THC.
While pure Ruderalis strains have little value in terms of fibre, medicine or psychoactivity, their auto-flowering capability and their extremely fast maturation time are of great interest to cannabis breeders. Hybrids made from combining Indica and Ruderalis strains are currently proving to be some of the earliest-maturing outdoor plants available.