2. Ethnobotany

Ethnobotanical data on Stevia species have been described since the 18th century. The latest revision covering ethnobotanical and ethnopharmacological aspects of the Stevia species was published in 2002 [6]. A literature survey covering the period January 2002–February 2021 was carried out here in order to update the information related to these topics.

The traditional uses of 29 species from Central and South America are available. Some of the most common popular uses of Stevia species are related to antidiarrheal, anti-inflammatory, antimalarial uses, as a febrifuge, a diuretic, a diaphoretic, to treat heart diseases, stomachaches, and skin conditions (Table 1).

Many plants such as S. connata, S. eupatoria, S. puberula, S. serrata, and S. subpubescens have been used for gastrointestinal disorders. Other species have been used as therapy for infectious diseases. In this sense, S. bogotensis, S. eupatoria, S. glandulosa, S. pilosa, and S. salicifolia have been employed as antipyrectic and antiparasitic. The anti-inflammatory use of Stevia plants has also been described in the literature; for instance, S. eupatoria, S. lucida, and S. salicifolia have been described as useful for the treatmet of inflammatory processes.

Stevia eupatoria, S. lucida, S. salicifolia, S. serrata, and S. subpubescens have been used in the United States, Mexico, and Central America and northern South America. These Stevia species have many associated medicinal properties and have been popularly used to treat a wide range of diseases.

Stevia eupatoria, known as “hierba del borrego”, “yerba del borrego”, and “cola del Borrego” has been described as antimalarial and has been used for its diuretic properties. Mexican folk medicine has used this species as an herbal remedy for stomach pain and for its hipoglycemic, analgesic, anti-inflammatory, and antihypertensive properties. This species is known as “estevia” (synonym of S. purpurea) [6,10,11].

Stevia lucida is widespread from Mexico to Venezuela. This plant is popularly known in Mexico as “yerba del aire” and “hierba de la araña”. In Guatemala, it is called “kebuj” and in Colombia, it is known as “chilca” and “golondrina de la sabanera”. In Venezuela, it is named “chilca” and “chirca”. Stevia glutinosa, a synonym of S. lucida, is called “javillo”, “javilla”, and “mariposa”. Several uses have been described for this species, including external use to relieve pain and treat wounds. In Colombia, a decoction of the aerial parts of S. lucida has been used to alleviate inflammatory processes. In Guatemala, it has been used to treat rheumatism. With the same purpose, in Maracaibo (Venezuela), a decoction of the leafy stems of S. lucida has been used. In Mexican folk medicine, “yerba del aire” has been used to treat chilly cramps [6,10].

S. salicifolia constitutes another species known with different common names and is distributed from southern United States to Mexico. In traditional medicine, it is known as “hierba del aire”, “hierba de la mula”, “zazal”, “zazale de olor, “yerba de la mula”, and “la envidia” in Mexico. This species, synonym of S. stenophylla, is also known as “hierba de la Santa Rita”. In Mercado Juarez (Toluca, Mexico), the dried aerial parts of S. salicifolia are marketed to prepare decoctions or alcoholic infusions that can be used “as a rub” to treat rheumatism. In Mexico, the decoction of the dried roots has been used as a cathartic, and the infusion of the roots has been recommended for intestinal upset due to parasites. The roots, mashed and placed in warm water, are used to prepare a drink employed as a purgative. The leaves are used to prepare tea (infusion) for colds and fevers [6,10].

Stevia serrata is known in traditional medicine as “ronino”, “uriki”, “otoninawa”, “chapo”, “yerba picante”, “hipericón”, “Q’ang’aj”, “anis silvestre”, and “hipericon arrie”. The external use of crushed roots of S. serrata for washes and poultices applied directly to open wounds has been reported. The whole plant crushed and rubbed has been employed in snake bites. This species has been described as a cough remedy and to treat gastrointestinal disorders [6,10,14].

In Mexico, S. subpubescens (synonym of S. subpubescens var. subpubescens) is commonly known as “zazal” and also as “hierba de la mula”. The aerial parts of this species have been recommended as a decoction to be used as a bath by women after parturition. The leaves are used for stomachaches and the whole fried plant can be rubbed on affected parts to treat joint pain [6,10].

Other species have also been described as medicinal. The decoction of S. macbridei has been used externally by women as a bath. The infusion or tea of S. nepetifolia has been suggested to alleviate dysmenorrhea symptoms. A drink prepared with the roots of S. balansae has been employed in Paraguay to treat diarrhea. The infusion of roots and flowers of S. trifida has been orally administrated to treat dysentery.

In the last years, several Argentinean Stevia species have been employed with an ornamental purpose. In this sense, S. achalensis, S. fiebrigii var. vattuonei, S. mercedensis var. mercedensis, S. sanguinea, S. satureiifolia var. satureiifolia and S. yalae can be mentioned. In particular, the species S. fiebrigii var. vattuonei and S. mercedensis var. mercedensis are commonly used in northern Argentina as ornamentation in religious festivities.