Botanical Identification of Stevia (Stevia rebaudiana)

To identify Stevia (Stevia rebaudiana) accurately, examine its morphological characteristics, taxonomic classification, and diagnostic features.

Stevia (Stevia rebaudiana) Monograph

Scientific Classification

Stevia rebaudiana belongs to the kingdom Plantae, division Magnoliophyta, class Magnoliopsida, order Asterales, family Asteraceae, genus Stevia, and species Stevia rebaudiana. These classifications define its taxonomic position in the plant kingdom.

The following table shows the full taxonomy of this medicinal plant.

Botanical Nomenclature and Synonyms

The scientific name of Stevia is Stevia rebaudiana, first described by the botanist Moctezuma in 1830. It is also known by several synonyms, including Stevia rebaudiana and Stevia nivea. Common names include sweet leaf, sugarleaf, and honey plant, while regional names vary by culture. Historically, it has been referred to as "honey plant" in South American indigenous languages.

Morphological Characteristics

Stevia rebaudiana is an upright, herbaceous plant with a fibrous root system. Its stems are square and branching, often hairy. Leaves are opposite, oval, and serrated, with a thick, fleshy texture. The inflorescence is a dense cluster of small, greenish-white flowers. The fruit is a dry capsule containing small, brown seeds.

Diagnostic Identification Features

Stevia rebaudiana can be distinguished by its opposite, lance-shaped leaves with serrated edges and its small, greenish-white flowers in clusters. It differs from similar species like Ruellia by having opposite leaves and a more compact growth habit. The presence of stinging hairs on the stems and leaves is another key identifying feature.

Natural Habitat and Geographic Distribution

Stevia rebaudiana is native to Paraguay and Brazil. It thrives in tropical and subtropical climates. It prefers well-drained, sandy soils. It is typically found at altitudes between 300 and 1,500 meters.

Phenology and Growth Cycle

Stevia rebaudiana blooms from late spring to early summer, typically between May and July in temperate climates. Seed formation occurs in late summer to early fall, around August to September. For identification purposes, the plant is often harvested during the early flowering stage, usually in mid to late summer, when leaves contain the highest concentration of steviol glycosides.

Phylogenetic Relationships

Stevia rebaudiana belongs to the Asteraceae family, sharing traits with other members like sunflowers and daisies. It is most closely related to species within the genus Stevia, particularly S. Americana. Its phylogenetic position reflects adaptations to similar ecological niches and morphological features.