Given our exhaustive use of the hemp and Cannabis plant - making use of the fiber, leaves, flowers, seeds and resin - it seems strange that there should be any element that has thus far escaped the notice of the modern herbalist. Perhaps because it usually spends its days hidden beneath the soil, the humble root is vastly under-explored, compared to the other components of the plant. However, looking at pre-prohibition medical- and veterinary literature, it is apparent that our ancestors (as with so many lost secrets and traditions) knew very well about its specific healing properties.
The first mention of hemp root as medicine can be found in the ancient Chinese pharmacopeia, the Shen Nung Pên-ts'ao Ching, as early as the third millennium BCE. It is stated that the juice of the root has diuretic properties, as well as being useful in assisting the cessation of hemorrhage after childbirth. Beyond its use in medicine, various Chinese texts attest to the importance of hemp root in 'gunpowder' preparations - it is roasted and powdered, before being mixed with bamboo root, pine pitch and various other substances, and ignited. There are several variations on the basic recipe, which result in incendiary powders, balls for catapults (which would ignite upon impact), smoke-powders and hand-grenades.
Elsewhere, it is stated that a paste made from the roots was used to relieve the pain of broken bones and surgical procedures. The Roman historian Pliny wrote in his Natural Histories, published circa 77-79 CE, that hemp root boiled in water could be used to relieve stiffness in the joints, gout and related conditions. He also noted that the root could be placed raw on burn wounds, but needed to be changed frequently to prevent drying out. Later, between the 4th and 5th centuries (CE), the Gaulish chronicler Marcellus Empiricus recorded in his opus De Medicamentis that the root was wrapped around the right arm, ostensibly as a treatment for worms.