Dioscoreaceae

Common Schmerwurz ( Dioscorea communis)

The Yamswurzelgewächse ( Dioscorea ), also called Yamsgewächse, Yamswurzgewächse or Schmerwurzgewächse are a family in the order of Yamswurzelartigen ( Dioscoreales ).

This family includes three genera with about 600-870 species. Their types are mainly used in warm to tropical climates. In Central Europe, only one type of Yamswurzelgewächse is native, the black bryony ( Dioscorea communis). Some species are stärkeliefernde food plants of several types in the ingredients for its medicinal effects are known.

Description

Habit and foliage leaves

These plant species grow as perennial herbaceous climbing plants or woody lianas, rarely shrubs. They usually form rhizomes or tubers as storage organs.

The leaves are rarely opposite, usually spirally arranged opposite one another and distributed to the stem axis. Often the leaves are divided into petiole and leaf blade, which is rarely seen in the monocot plants of the case. On the often large leaves extra-floral nectaries are often present. The leaf blades are simple or compound; the Blattnervatur is Palmat and the leaf edge smooth.

Inflorescences and flowers

The flowers are borne in inflorescences differently constructed. There are getrenntgeschlechtige, mostly dioecious ( dioecious ), but there are also monoecious ( monoecious ) taxa.

The usually unisexual, in Stenomeris hermaphrodite flowers are triple and radial symmetry. The bloom are alike and have six tepals. In the flowers nectaries are present. In the male flowers two circles, each with three stamens are usually present. Either all stamens fertile or that of a circle are transformed into staminodes. The three carpels are fused into a at constant ( syncarp ) ovary. The flowers formula is:

Fruits

Are formed different fruits. There are usually three -edged, lokulizide capsule fruits, rarely fleshy berries and seeded Samara.

Ingredients and use

Yamswurzelgewächse contain flavonols and calcium oxalate. In plants, parts of the Yamswurzelgewächse are often Steroidsaponine to find (eg diosgenin ); they can serve as starting material for semi-synthetic production of certain hormones.

Many species are cultivated in the tropics as crops ( yams ). For example, is grown in East Asia Dioscorea batatas. Its underground tubers are edible and in the tropics is an important starch supplier.

As a " succulent " ornamental plants, some species ( Dioscorea elephantipes (L' Hér ) Engl, Dioscorea mexicana, Dioscorea sylvatica, Dioscorea macrostachya Bentham ( Syn: Testudinaria macrostachya ( Bentham ) Rowley ). ) Used; However, they are not succulent, but have interestingly shaped tubers.

System

The first publication of the surname was in 1810 by Robert Brown in Prodromus Novae Florae Hollandiae, 294 The type genus Dioscorea L. is a long time were the only species that are now classified in the genus Dioscorea to this family.; the types of some former genera have been incorporated into the Dioscorea since 2000. Some authors also annexed the Tacca, which represent a separate family Taccaceae, here. The genera of the formerly independent families Avetraceae Takht. , Stenomeridaceae J.Agardh, Tamaceae Bercht. & J.Presl, Tamnaceae J.Kickx f and Trichopodaceae Hutch. now the family of Dioscoreaceae R.Br. assigned.

Here are the three genera of Yamswurzelgewächse ( Dioscorea ):

  • Yams ( Dioscorea L., Syn: Borderea Miégev, Botryosicyos Hochst, Elephantodon Salisb, Epipetrum Phil, Hamatris Salisb, Helmia Kunth, Higinbothamia Uline, Hyperocarpa ( Uline ) GMBarroso, Merione Salisb, Nanarepenta Matuda, Oncorhiza. .. .. Pers., Oncus Lour. , polynomials Salisb. , Rajania L., Rhizemys Raf., Ricophora Mill, Sismondaea Delponte, Strophis Salisb. , Tamus L., Tamnus Mill, Testudinaria Salisb. Burch ex. , Ubium JFGmel. ) She is pantropical with today about 600 ( 350 to 800 ) types.
  • Stenomeris Planch. ( Syn: Halloschulzia Kuntze ): With two species in the western Malay Archipelago.
  • Trichopus Gaertn. ( Syn: Avetra H.Perrier ): With two ways: Trichopus sempervirens ( H.Perrier ) Caddick & Wilkin ( Syn: Avetra sempervirens H.Perrier ) in Madagascar.
  • Trichopus zeylanicus on the Indian subcontinent and the Malay Peninsula.

Pictures

Dioscorea balcanica:

A fruiting plant begins to "feed " which means that the nutrients can be stored in the underground storage organs and die at the end of the aerial parts of the vegetation period.

Swell

  • Description of the family of Dioscoreaceae in APWebsite. ( in English)
  • Description of the family of Dioscoreaceae and description of the family of Trichopodaceae at DELTA by L. Watson & MJ Dallwitz. ( in English)
  • Lauren Raz: Dioscoreaceae in the Flora of North America, Volume 26, p 479: Online.
  • Chih -chi Ting & Michael G. Gilbert: Dioscoreaceae in the Flora of China, Volume 24, 2000, p 276: Online.
  • Lizabeth R. Caddick et al. Yams and Their allies: Systematics of Dioscoreales, in:. KL Wilson & DA Morrison (Editor): Monocots: Systematics and Evolution, Melbourne, 2000, pp. 475-487. .
  • Lizabeth R. Caddick, Paul Wilkin, Paula J. Rudall, Terry AJ Hedderson & Mark W. Chase: Yams Reclassified: a recircumscription of Dioscoreaceae and Dioscoreales in Taxon, 51 (1 ), 2002, pp. 103-114. .
  • Entry in the Western Australian flora.
Robert Brown (botanist) Perennial plant Vine Ovary (botany) Berry
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