Two-nodular crow's foot

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Two-nodular crow's foot
Two-nodular crow's foot (Lepidium didymum)

Two-nodular crow's foot ( Lepidium didymum )

Systematics
Rosids
Eurosiden II
Order : Cruciferous (Brassicales)
Family : Cruciferous vegetables (Brassicaceae)
Genre : Cress ( Lepidium )
Type : Two-nodular crow's foot
Scientific name
Lepidium didymum
L.

The two-nodal crow's foot ( Lepidium didymum ) is a species of the cress ( Lepidium ) in the cruciferous family (Brassicaceae). South America is assumed to be the original range of the species, which now occurs worldwide.

features

The herbaceous plant , which is usually annual , rarely also biennial, reaches a length of 10 to 45 (rarely up to 70) cm. It gives off a foul smelling odor. The plant is hairless or has straight plant hairs about 1 mm long. The stems grow prostrate to ascending and are usually branched at the base.

The alternate leaves are petiolate and pinnate. The basal leaves are pinnate almost to the midrib and 4 to 10 cm long. On both sides of the spindle, 2 to 7 mm long, serrated or incised, pointed flaps on the sides. The middle leaves are similar to those at the base and measure 1.5 to 4.5 × 0.5 to 1.2 cm. The leaves gradually get smaller towards the top and are less divided. The lobes are elongated lanceolate to elliptical.

Opposite the stem leaves are the racemose inflorescences . The pedicels are longer than the flowers. The white to yellowish egg-shaped petals are 0.4 to 0.5 mm in size. They are shorter than the sepals and can be completely absent. The two (or rarely four) stamens have white stamens and purple anthers . The flowering period is mainly March to June.

The 2 mm long stalked pods consist of two almost spherical halves, are edged, reticulate, wrinkled and without jagged edges. The width of the pods is 2 to 3 mm. The fruit bodies are hairless, slender ascending or slightly bent back with a size of 1.5 to 2.5 mm.

The plant has the number of chromosomes 2n = 32.

Two-nodal crow's foot ( Lepidium didymum ), inflorescence with young fruits

Occurrence

The two-nodular crow's foot is originally found in South America, but is a neophyte in Europe, Africa, Asia, Australia, New Zealand, North America, Mexico and on islands in the Pacific. The two-nodular crow's foot prefers to grow in nitrogen-rich, bright and warm places. It is widespread worldwide and mainly settles near the coast at altitudes of up to 1000 m. The preferred sites are roadsides and waste areas and fields with companies of the Association Polygono-Chenopodion or impact plant communities of the Association Polygonion avicularis .

Synonyms

Synonyms for Lepidium didymum L. are: Carara didyma (L.) Britton , Coronopus didymus (L.) Sm. , Coronopus pinnatifida DC. , Senebiera pinnatifida DC. , Senebiera didyma (L.) Pers. , Senebiera incisa Willdenow .,

Sources and further information

The article is mainly based on the following documents:

Individual evidence

  1. ↑ a b c Lepidium in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland. Retrieved July 28, 2017.
  2. ↑ a b Erich Oberdorfer : Plant-sociological excursion flora for Germany and neighboring areas . With the collaboration of Angelika Schwabe and Theo Müller. 8th, heavily revised and expanded edition. Eugen Ulmer, Stuttgart (Hohenheim) 2001, ISBN 3-8001-3131-5 , pp.  446 .
  3. ↑ Flora of North America , accessed June 28, 2010.

Web links

Commons : Two-nodular crow's foot ( Lepidium didymum )  - album with pictures, videos and audio files