Stevia (genus)

Stevia is a genus of about 240 species of herbs and shrubs in the sunflower family (Asteraceae), native to subtropical and tropical regions from western North America to South America. The best-known species, Stevia rebaudiana, is cultivated for its sweet-tasting leaves, which are the source of steviol glycosides, a group of natural sweeteners marketed under various trade names.

Description

Members of the Stevia genus are typically perennial plants, although some may be annuals. They vary in size from small herbs to larger shrubs. Leaves are usually opposite and can be toothed or smooth-edged. Flowers are small and usually white, arranged in corymbs. The genus is characterized by its complex chemistry, particularly the presence of various diterpene glycosides.

Taxonomy

The genus Stevia was first described by Ruiz and Pavón in 1794. Its placement within the Asteraceae family is well-established. Botanical classification within the genus can be complex due to morphological similarities between species and natural hybridization.

Cultivation and Uses

Stevia rebaudiana is the primary species of commercial interest. It is cultivated in numerous countries for its sweetening properties. The steviol glycosides extracted from the leaves are used as sugar substitutes in food and beverages. Cultivation practices vary depending on the region but generally involve well-drained soil, sufficient sunlight, and appropriate irrigation.

Ecology

Stevia species are found in a variety of habitats, including grasslands, forests, and disturbed areas. They play a role in supporting local ecosystems, providing food and shelter for various insects and other animals.

Conservation Status

The conservation status of various Stevia species varies. Some species are relatively common and widespread, while others are rare or threatened due to habitat loss or other factors. Further research is needed to assess the conservation status of many Stevia species.