Stevien

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Stevien
Stevia rebaudiana

Stevia rebaudiana

Systematics
Euasterids II
Order : Astern-like (Asterales)
Family : Daisy family (Asteraceae)
Subfamily : Asteroideae
Tribe : Eupatorieae
Genre : Stevien
Scientific name
Stevia
Cav.
Stevia rebaudiana inflorescences

The stevia ( stevia ) are a genus of plants that belongs to the sunflower family (Asteraceae). The distribution area extends from the western USA (seven species), over Mexico, Central to South America . The best-known and economically most important species is Stevia rebaudiana , which is widely used as the basis for the sweetener stevia among indigenous peoples of South America, but now especially in Asia .

description

Vegetative characteristics

Stevia species grow as annual to perennial herbaceous plants , semi-shrubs to shrubs that reach heights of between 0.5 and 1.20 meters. The upright stem is usually branched.

The opposite or alternate leaves are stalked or sessile. The differently hairy to hairless, sometimes shiny or glandular dotted leaf blade can be shaped very differently depending on the species, has one or three main nerves and a smooth, serrated or toothed leaf margin.

Generative characteristics

The basket-shaped partial inflorescences stand together in loose to dense, umbrella-clustered total inflorescences . The disc-shaped flower heads have a diameter of 1 to (mostly) 2 to 3 mm. The mostly five, rarely six in a row, more or less the same bracts are two- to three-nerved. The flat to convex base of inflorescence is hairless. Each flower head usually contains five, rarely six flowers.

The five purple to pink or white petals are funnel-shaped fused with a narrow throat. The corolla is three to four times as long as its diameter and more or less hairy on the inside. The mostly smooth, sometimes papillary styles have two thread-like style branches.

The columnar to prismatic or spindle-shaped achenes are five-ribbed, dotted with glands and / or rough. The pappus consists of five free or overgrown bristles and scales.

The chromosome numbers found were n = 11, 12, 17.

Systematics

The genus name Stevia was 1797 by Antonio José Cavanilles in Icones et Descriptiones Plantarum, qua aut sponte ... , 4 (1), 32, panel 354 first published . The lectotype used was Stevia salicifolia Cav. set. Synonyms for Stevia Cav. are: Metastevia Grashoff , Mustelia Spreng. The generic name Stevia honors the Spanish doctor and botanist Pedro Jaime Esteve (approx. 1500–1556).

The genus Stevia belongs to the tribe Eupatorieae in the subfamily of Asteroideae within the family of Asteraceae .

There are around 240 types of stevia (selection):

literature

  • Guy L. Nesom: Stevia in the Flora of North America , Volume 21, 483: Online. (Section description, distribution and systematics)

Individual evidence

  1. a b c d e f g h i j k l m n o p q r s t u v w x y z Stevia in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland. Retrieved February 26, 2018.
  2. Lotte Burkhardt: Directory of eponymous plant names . Extended Edition. Botanic Garden and Botanical Museum Berlin, Free University Berlin Berlin 2018. [1]
  3. a b c d e f Guy L. Nesom: Stevia Cavanilles. In: Flora of North America, vol. 21. [2] .

Web links

Wiktionary: Stevia  - explanations of meanings, word origins, synonyms, translations
Commons : Stevia  - collection of pictures, videos and audio files