Dioscorea mexicana

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Mexican yam
Dioscorea mexicana.jpg
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Monocots
Order: Dioscoreales
Family: Dioscoreaceae
Genus: Dioscorea
Species: D. mexicana
Binomial name
Dioscorea mexicana

Dioscorea mexicana, Mexican yam or cabeza de negro is a species of yam in the genus Dioscorea.

Dioscorea mexicana is a caudiciform dioscorea having either a partly to completely above-ground dome-shaped caudex with a thick, woody outer layer up to 3 feet(90 cm) in diameter and 8-10 inches(20 to 25 cm) in height. The caudex of D. mexicana is divided into regular polygonal plates that become protuberant with age, and separated by deep fissures. The shockingly vigorous annual vines which may reach 30 feet (9 m) long before dying back in winter, that grow up from the caudex, bear heart-shaped leaves.[1]

It ranges from the state of Veracruz in Mexico south to Panama. It is notable for its production of diosgenin, which is a precursor for the synthesis of hormones such as progesterone.[2] Russell Marker developed the extraction and manufacture of hormones from D. mexicana at Syntex. Later the Mexican barbasco trade focused instead on Dioscorea composita instead, as this variety has a higher diosgenin content.[3]

References[edit]

  1. ^ Dortort,Fred(2011).Succulent Plants of the World.Timber Press Inc. pp 220. ISBN 978-0-88192-995-9
  2. ^ ars-grin.gov
  3. ^ americanheritage.com

External links[edit]