If a psychedelic compound can completely shatter our perception of reality, then it could induce psychosis or psychotic episodes in people that require hospitalisation – thereby further straining the healthcare system. Additionally, there is a lack of research and knowledge on the exact mechanisms by which DMT acts on the brain, which is a contributor to DMT being classed as a drug and therefore controlled.
In the case of DMT, in a number of countries it is illegal to extract it, possess it, use it and sell it.
However, possession of a plant that contains DMT is legal, mainly because nearly every plant contains it so it is not possible to control, although it may be illegal to possess some species of plants, specially those known to contain high levels of DMT.
As an example of plants that cannot be controlled, the Australian national floral emblem is called “Acacia pycnantha”, commonly known as the Golden Wattle, which contains small traces of DMT throughout the plant, ~ 0.4%. While other acacia species like “Acacia aneura” can contain between 2-6% of DMT in the dried leaves. https://en.wikipedia.org/wiki/List_of_Acacia_species_known_to_contain_psychoactive_alkaloids
If the plant is not illegal then it is your decision as to whether you should ingest that plant material, but don't be fooled by thinking you can start having ceremonies. These types of ceremonies may be illegal due to safety concerns.
Note: Check the local laws within your own country or state in order to ensure you are not breaking them.