Salvia divinorum (Epling and Játiva-M.) is a perennial herb in the Labiatae (mint family) native to certain areas in the Sierra Mazateca of Oaxaca, Mexico (Fig. 1). It is one of about 500 species of Salvia in the New World subgenus Calosphace (Epling and Játiva-M.. 1962). The plant grows in large clones to well over 1 m in height and its large green leaves, hollow square stems and white flowers with purple calyces are characteristic taxonomic features. This sage has been found only in forest ravines and other moist humid areas of the Sierra Mazateca between 750 m and 1500 m altitude (Díaz, 1975a). Carl Epling, who first described S. divinorum, reported the flower as having a blue corolla, and it has been illustrated this way in the literature (Epling and Játiva-M, 1962; Schultes, 1976). However, this description has been shown to be an error, as all living specimens of the plant have had blossoms with white corollas and purple calyces (Díaz, 1975a; Emboden, 1979).

S. divinorum is one of several vision-inducing plants employed by the Mazatec Indians, one of the native peoples living in the mountains and upland valleys of northeastern Oaxaca. Unlike other Mexican tribes, there is little information concerning their existence before the arrival of the conquering Spanish, who reduced the Mazatecan population through exploitation and disease (Weitlaner and Hoppe, 1964). The 1970 census estimated their number at 92,540 (Córtes, 1979) and the language, of the Mazatec-Popoloca family, is one of the many non-Spanish dialects spoken throughout Mexico (Weitlaner and Hoppe, 1964). The Mazatecan ritual use of hallucinogens, such as mushroom containing psilocybin and morning glory seeds containing lysergic acid amide, has been widely publicized through the investigations of R. Gordon Wasson and Albert Hofmann, among others (Wasson and Wasson, 1957; Wasson, 1963; Hoffman, 1964; Hoffman, 1980).