Cannabis Sativa is normally a tall plant, and is 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 Cannabis Indica. In general, the foliage of a Sativa plant is somewhat sparser than that of the other varieties. This allows for more air flow around and between the plants, resulting in healthier growth and less risk of fungus in humid tropical conditions.
How the Equatorial Origins of Sativa Strains Affect Their Growth:
Cannabis Sativa grows taller than the other types of cannabis, gaining height all through its growing and flowering phases. This is due to the tropical origin of Sativa strains. In the regions close to the equator, the length of day does not change very much throughout the year, so Sativa strains are adapted to accomplish both their growing and flowering in a short, fairly uniform photoperiod. In this way they are at the opposite end of the cannabis spectrum to Ruderalis strains.
The female flowers of Cannabis Sativa start at the nodes (the points at which pairs of leaves grow from the stem and branches) and usually expand along the length of the stem and branches, instead of clustering around the nodes, 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, despite being larger in size.
Cannabis Sativa Hybrids:
Pure strains of Cannabis Sativa often require a combined growing and flowering period of around six months to ripen completely. For this reason pure Sativa strains are rarely used for indoor cultivation or sold as commercial cannabis seeds. All Sativa strains that are viable for indoor growing have been cross-bred with Indica strains in order to reduce their height and flowering time. Even so, Sativa-Indica hybrids generally have a longer flowering period than their Indica relatives.
General Physical Appearance of Indica Strains
The typical example of Cannabis Indica is a more compact, thick-stemmed bush than its cousins, usually reaching a height of less than two metres. The foliage is generally a dark shade of green, some examples appearing to have almost blue or green-black leaves. These leaves are composed of short, wide blades.
Growth and Flowering Cycle of Cannabis Indica
The life cycle of Cannabis Indica is divided into two distinct phases - growing and flowering – which are reactions to different day-lengths (photoperiods).
Indica strains require both a growing and a flowering period in order to reach their full size.
Origins of Ruderalis:
Cannabis Ruderalis is tentatively described as the third type of cannabis, as botanists are unsure whether it qualifies as a species in its own right. Ruderalis is an uncultivated strain native to Russia, central Europe and central Asia 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 types of cannabis 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 environments encountered by the original tropical phenotype Cannabis Sativa L. As it spread further and further north of the equator after the last ice age, the different types evolved to survive in new climates. Human intervention and agriculture has also had significant effects on Indica and Sativa gene-pools, but much less influence on wild Ruderalis.
A typical Cannabis Ruderalis plant is very short in height, often between 30cm and 80cm when fully grown. It produces only a few branches and has wide, fat-bladed leaves, similar to those of Cannabis Indica. Once flowering begins, Ruderalis will gain even less height than an Indica strain.
The Auto-Flowering Ability of Cannabis Ruderalis:
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.
Nearly all flowering plants take their cue to reproduce from seasonal changes in the climate, particularly the number of hours of daylight. The ability to begin flowering based on changes in the plant instead of its environment is known as ‘auto-flowering’.
Cannabis Ruderalis will begin flowering when it achieves a certain stage of maturity - around the time it produces its fifth to seventh pair of leaves (fifth to seventh node), which normally occurs after about five to seven weeks of growth. Once Cannabis Ruderalis has begun flowering, it continues to do so until other environmental factors (most notably winter) cause the plant to die. The other varieties of cannabis may expire naturally once they have accomplished reproduction, or may return to vegetative growth if given a long photoperiod.
Fast Growth Cycle
The adaptation of Cannabis Ruderalis 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 (though 12 to 14 weeks is more common). 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.