Cystolithic hairs

The Cystolithic hairs are a spindle-shaped body consisting of pectin-associated concentric layers of longitudinally aligned cellulose microfibrils and other cell wall of polysaccharides.

Cystolithic hairs contain Calcium Carbonate(CaCO3).

Cystoliths Hairs on Leafs

Cannabis sativa also known as Marijuana, is a very famous plant and analyzed in many forensic laboratories in the case of poisoning, plant analysis, etc. This plant is mainly identifies by trichomes (Cystolith hairs) on plant particles. It is mainly found on leaf surfaces of the plant.

Marijuana

Source:

Marijuana Identification: A Test for Calcium in Cystolithic Hairs
Baruch Giattstein and Azriel Gorski, Israel National Police