Cannabis sativa and Cannabis indica are sources of industrialhemp and medicinal marijuana, respectively. Jean Baptiste Lamarck, in 1785, identified Cannabis Indica from hemp plants found growing in Northern India. It has a resinous body that protects it from the harsh winters of the region. The plants have higher intoxicating properties. Locals make hashish from this species.
Cannabis sativa is also used in medicine and as a recreational weed. Thevariety used for medical and recreational purposes are tall and thin with narrower leaves and a light green color. Hemp plants from Europe are short with broader and greener leaves and no psychoactive properties.
Marijuana-yielding plants are morphologically nearly indistinguishable from industrial hemp cultivars, but marijuana varieties are more branched and bushy whereas industrial hemp producing plants are straight with fewer branches.
Cannabis plants are annual herbs. Plant height rarely goes beyondfive meters. Leaves are palmate with lanceolate, serrate leaflets 10 centimeters long and 1.5 centimeter broad. The species is probably native to the Central Asian region. It is cultivated across many parts of Asia, Europe, and China. It is an introduced species in the US and North Africa.
Cannabis plants can be seen growing in the wild in degraded forestsites in India. Cannabis plants can be seen growing in the wild along roads and can survive in a wide range of soil and climate conditions. The resistance of the species to ground frost and waterlogging is quite low.
Cannabis belongs to the Urticaceae family. There are large numbers of cultivars of Cannabis, many of which are named after the locality in which they are found.
Interbreeding is easy and common in nature. Most natural crops are composed of multiple cultivars, each with its own set of characteristics. Cultivars good for fiber have longer stalks, branch very little, and yield only small quantities of seed. Profusely seeding varieties are short and mature early. Drug-yielding varieties too are short. They are much branched and have smaller, dark-green leaves.
As the plant is a rapid interbreeder, industrial hemp, oilseeds, and medicinal or recreational marijuana yielding plants should be cultivated in separate plots. Cross-pollination affects the content of THC (tetrahydrocannibol), the primary psychoactive molecule in the plant. Higher levels of THC will make the crop unsuitable for industrial hemp production.
To know more about the botany, industrial, recreational and medical uses of this herb, you can take a look here.