Cannabis blooms once a year. Its vegetative growth begins in spring and goes through its cycle until the end of its flowering and fertilisation stages in autumn and winter, although this process varies significantly depending on which latitude the plant is growing. The first hemp plant was classified by botanist Carl Linnaeus in 1735, publishing its scientific name “Cannabis sativa.” Under this label, he compiled all its varieties. Years later, another scientist, Jean-Baptiste Lamarck (1744-1829), described a second variety, which he named Cannabis sativa indica. Later on, in 1924, botanist D. E. Janischevsky identified a third variety, Cannabis sativa ruderalis.
According to written records, botanists had first classified cannabis within the nettle, or Urticaceae family. After a rectification, these species were included within the fig, or Moraceae family. However, today they stand as an independent, specific family that only encompasses hemp and hop.
Cannabis sativa sativa
Skinny and with a wide internodal space, these plants can grow up to five meters high. Their leaflets—the parts of a compound leaf—are long and thin. They flower late in the growing season, so indoor growing is not advisable. This variety is typical of subtropical zones near the equator. Its flowering stage can extend over fourteen weeks and its buds look smaller when compared with its indica counterparts.
Cannabis sativa indica
This variety stretches up to one to two meters high and the space between its branches is far more reduce than in the case of sativa. Its leaflets are broader and shorter. Indica plants stand out from other cannabis varieties because of their their thick buds and their shorter flowering stage—around nine weeks. The indica strain is originally from mountain areas far from the tropics.
Cannabis sativa ruderalis
Ruderalis plants can barely reach over one meter high. They grow all year round on low temperature areas and their leaves, as well as their flowers, are rather small. Apart from this, these plants have a remarkably low THC content.
Nowadays, cannabis has spread to such extent that hybrids have been bred from these three varieties with the purpose of obtaining the right amount of THC or CBD, depending on the use.
WHO Cannabis Classification
Until December 2020, the UN had included cannabis and its resin (hash) in one of the most restrictive schedules established under the Single Convention on Narcotic Drugs of 1961 Cannabis was listed in Schedule I, along with heroin and cocaine, and Schedule IV, comprising drugs with “particularly dangerous properties,” of little to no therapeutic use.
The WHO carried out the first critical review on the health risks and medical properties of cannabis. In 2019, this organisation published a series of recommendations to reclassify cannabis and related substances within the UN drug control system. From all these recommendations—debated on by the 53 Member States of the Commission—only one was approved: removing cannabis from List IV of the Single Convention of 1961. The WHO has formally acknowledged the medical benefits of cannabis, providing easier access to this drug and removing hurdles in research.