Chinese foxglove

Description

Rehmannia elata, the Chinese foxglove, is a species of flowering plant in the family Orobanchaceae, native to China. Growing to 150 cm (59 in) tall by 50 cm (20 in) broad, it is an herbaceous perennial with veined, hairy leaves and pink, tubular flowers with darker pink stripes in summer. The flowers bear a superficial resemblance to foxgloves, hence the common name "Chinese foxglove", which is also applied to the whole genus. However this species is not closely related to the true foxglove (Digitalis). The plant has gained the Royal Horticultural Society's Award of Garden Merit. Rehmannia is a genus of seven species of flowering plants in the order Lamiales and family Orobanchaceae, endemic to China. It has been placed as the only member of the monotypic tribe Rehmannieae, but molecular phylogenetic studies suggest that it forms a clade with Triaenophora. 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. A 2016 classification of flowering plants, the APG IV system enlarged Orobanchaceae to include Rehmannia, making it one of the few genera in the family, along with Lindenbergia, not to be parasitic. Sometimes known as Chinese foxglove due to its superficial resemblance to the genus Digitalis, the species of Rehmannia are perennial herbs. The plants have large flowers and are grown as ornamental garden plants in Europe and North America, and are used medicinally in Asia. Rehmannia contains the vitamins A, B, C, and D, as well as other compounds, such as catalpol, an iridoid glycoside.