Gently blowing the perfumed smoke on their heads, arms, legs and into their mouths, Avila aims to purify the students' minds and bodies from negative energies.

Avila is a Mexican curandera, or healer, invited by the University of New Mexico to participate in a two-week course on the practice of indigenous folk medicine, also known as curanderismo, in Mexico and other Latin American countries.

A steady stream of Latino immigrants is fueling the demand for curanderismo in the Southwest. Often misunderstood as witchcraft, the practice also has piqued the interest of doctors trying to educate themselves about different approaches to medicine and healing.

Curanderismo is a holistic, spiritual approach to medicine that uses the natural world to heal the mind, body and soul. Curanderas often prepare teas, creams and tinctures from herbs and plants and use massage therapies to treat many ailments.

''Mexicans and Hispanics have been doing this type of medicine for centuries,'' said Eliseo ''Cheo'' Torres, vice president for student affairs at UNM who started the course. Curanderismo "is a mixture of knowledge and ritual and indigenous medicine. Not only is it a healing practice, it is a source of pride for Latinos. It is part of our culture.''

Beyond creating plant-derived remedies, curanderas are revered in the Latino culture as people with a gift of healing and supernatural intuition. Such healers often are perceived as holding the fate of their patients in their hands, procurers of life and death.

Marco Antonio Campos Romeu, a curandero from Mexico City, will treat a baby's earache with a drop of hand-mashed garlic oil or recommend a cup of cascara sagrada tea for a patient with digestive problems.

But for psychological ailments such as post-traumatic stress, anxiety or depression, Romeu might try a combination of treatments such as incense, massage, candle rituals and sweat cleansing ceremonies.

''I don't make magic potions or anything like that. I treat people with la vida de las plantas [the life of plants] and the forces of life,'' Romeu said.

One of the major appeals of curanderismo and folk medicine in general is that it's cheap and accessible, especially for people in rural areas.

Curanderismo is also finding a new audience with people disillusioned with traditional Western medicine, opting instead for a more natural, personal and affordable form of treatment.

Ben Daitz, doctor and professor emeritus at University of New Mexico's Department of Community Medicine who has treated patients who also seek the help of curanderas, said people should use caution with folk medicine in the same way they do with other major health decisions.

''We have to be aware of the limits of curanderismo because there is no evidence to show that treatments are effective, and people can be mislead,'' Daitz said. ''When using herbal remedies, people need to know when they are an effective treatment and when they are not. I worry that people who have diseases like diabetes, hypertension and arthritis are not taking proper steps to ensure proper treatment.''