Pointed burrs

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Pointed burrs
Elbe pointed burdock (Xanthium albinum subsp.albinum)

Elbe cocklebur ( Xanthium albinum subsp. Albinum )

Systematics
Euasterids II
Order : Astern-like (Asterales)
Family : Daisy family (Asteraceae)
Subfamily : Asteroideae
Tribe : Heliantheae
Genre : Pointed burrs
Scientific name
Xanthium
L.

The pointed burdock ( Xanthium ) are a genus of plants from the subfamily Asteroideae within the sunflower family (Asteraceae).

description

Illustration of common pointed burdock ( Xanthium strumarium )

Xanthium species usually grow as annual herbaceous plants that reach heights of 10 to over 200 centimeters. The upright stems are branched. The mostly alternate (two to six can also be opposite) leaves are stalked and simple to lobed. The leaf margin is smooth to toothed.

Xanthium species are single sexed ( monoecious ). The disc-shaped, small, cup-shaped inflorescences are rarely found individually, mostly in branched overall inflorescences . The flower heads contain only flowers of one sex. The male flower heads are flattened plate-shaped, have a diameter of 3 to 5 mm, contain 6 to 16 bracts in one or two rows and 20 to over 50 functionally male flowers with whitish, funnel-shaped, five-lobed corollas . The stamens are fused. The female flower heads have a diameter of 2 to more than 5 mm during the flowering period and later as fruit baskets they have a diameter of 6 to over 20 millimeters. Their 30 to over 75 bracts are in six to over twelve rows; their tips are more or less curved and form hard thorns as the fruit ripens. The female flower heads contain only two flowers without petals.

Thorny pointed burdock ( Xanthium spinosum )
The "burdock" are the diaspores of the xanthium species, here from the common pointed burdock ( Xanthium strumarium ).

The black achenes have no pappus and are distributed in the thorny, two-chambered fruit baskets (in this case the diaspores ), the "burdock". They use the burdock effect by getting caught on the fur of animals passing by or on floating debris and thus spreading them out.

Systematics and distribution

The genus Xanthium was established by Carl von Linné . The botanical genus name Xanthium is derived from the Greek word xanthos for yellow and refers to the fact that a yellow dye was previously obtained from one of the species.

The xanthium species are originally native to the New World . They are neophytes in much of the world .

The pointed burdock should not be confused with the species burdock ( Arctium ), for example Great Burdock , Arctium lappa .

The systematics of the genus pointed burdock ( Xanthium ) is controversial. In the genus of the pointed burdock ( xanthium ) there are two to three (4 to 25 species depending on the author):

  • Shore pointed burdock ( Xanthium albinum ( Widder ) H. Scholz ): With two subspecies:
    • Elbe pointed burdock or thick-headed bank pointed burdock ( Xanthium albinum L. subsp. Albinum )
    • Eastern Shore cocklebur or Slim-headed Shore cocklebur ( Xanthium albinum subsp. Riparium (Čelak.) Aries & Wagenitz )
  • Thorny pointed burdock ( Xanthium spinosum L. )
  • Common pointed burdock or stinging pointed burdock ( Xanthium strumarium L. , Syn .: Xanthium pungens Wallroth , Xanthium sibiricum Patrin ): With several varieties:
    • Canadian cocklebur or Italian cocklebur , Orient cocklebur , Large fruited cocklebur, sugar cocklebur ( Xanthium strumarium var. Canadense (Mill.) Torr. & A.Gray , Syn .: Xanthium italicum Moretti , Xanthium orientale L. , Xanthium saccharatum Wallr. )
    • Xanthium strumarium var. Glabratum (DC.) Cronquist
    • Xanthium strumarium var. Japonicum (Aries) Hara
    • Xanthium strumarium L. var. Strumarium

use

The green parts of the plant and the seeds of some species can be eaten raw or cooked. Some species are used medicinally.

literature

Individual evidence

  1. ^ A b Xanthium in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland.
  2. ↑ John L. Strother: Xanthium Linnaeus , p. 19 - same text online as the printed work , In: Flora of North America Editorial Committee (Ed.): Flora of North America North of Mexico , Volume 21 - Magnoliophyta: Asteridae (in part) : Asteraceae, part 3 , Oxford University Press, New York and Oxford, 2006. ISBN 0-19-530565-5
  3. ↑ Entries on Xanthium in Plants For A Future

Web links

Commons : Pointed Burdock ( Xanthium )  - Collection of images, videos and audio files