Rehmannia piasezkii

Description

Rehmannia is a genus of six species of flowering plants in the order Lamiales and family Orobanchaceae, endemic to China.It is the only member of the monotypic tribe Rehmannieae.Contrary to the immense majority of the taxa of Orobanchaceae, Rehmannia is not parasitic. Rehmannia is named for Joseph Rehmann (1788–1831), a physician in St. Petersburg. The name "Rehmannia" has also been given to a genus of Jurassic ammonites of the family Reineckeidae. The genus was included in the family Scrophulariaceae or Gesneriaceae in some older classifications. The current placement of the genus is in neither Scrophulariaceae s.s. nor Plantaginaceae s.l. (to which many other former Scrophulariaceae have been transferred). Earlier molecular studies suggested that its closest relatives were the genera Lancea and Mazus,which have been included in Phrymaceae.Subsequently, it was found that Rehmannia groups with Triaenophora, and both taxa are jointly the sister group to Lindenbergia and the parasitic Orobanchaceae.Recently, the latest classification of flowering plants, the APG IV, enlarged Orobanchaceae to include Rehmannia, making it the only other genus, along with Lindenbergia, to not be parasitic within the family.