Final answer:
A practitioner who uses the Visionary Vine, often referring to Ayahuasca, is called a Yachac. This term is associated with a shaman or wise person within Amazon indigenous cultures, known for their knowledge of medicinal plants and spiritual practices.
Step-by-step explanation:
The term for a practitioner that uses the Visionary Vine, which is often a reference to the psychotropic brew Ayahuasca, is a Yachac. In the indigenous cultures of the Amazon, a Yachac (which can also be spelled as Yatiri) is known to be a wise person or shaman who has extensive knowledge of medicinal plants, healing, and spiritual practices of their community. These practitioners are often sought after for their abilities to heal both physical and spiritual ailments through the use of traditional medicine, including the Visionary Vine, and play a vital role in the cultural and spiritual life of their people.