Small rock cress
| Small rock cress | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Small rock cress ( Hornungia petraea ) |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Hornungia petraea | ||||||||||||
| ( L. ) Rchb. |
The small rock cress ( Hornungia petraea (L.) Rchb .; Syn .: Hutchinsia petraea (L.) R.Br. ), also known as dwarf steppe cress , is a member of the cruciferous family (Brassicaceae) that is rarely found in Central Europe . It blooms mainly from April to June.
Appearance
The annual herbaceous plant reaches a height of only two to 15 centimeters. It is almost bald or has few, short, branched hair. The stem is branched and leafy. The leaves are deeply pinnate, the lowest are in a basal rosette and are petiolate. The sepals are usually purple in color and have a white skin edge. The white petals are up to a millimeter long and only slightly longer than the calyx. The fruit stalks are bare. The pods are ellipsoidally shaped, about two to three millimeters long and blunt. The valves have a distinct median nerve . The scar is almost sessile and does not protrude beyond the border at the tip of the pod. There are one or two seeds in each compartment .
The number of chromosomes is 2n = 12.
Occurrence
Location requirements
The small rock cress grows in dry grass communities such as on rocks, in cracks in the earth and other, especially warm, lime-rich stone soils . In Central Europe it is a character species of the Cerastietum pumili from the Alysso-Sedion association, but also occurs in gappy societies of the Xerobromion association.
General distribution
Hornungia petraea occurs from Central Europe to the Mediterranean and North Africa . It is widespread to the east as far as Asia Minor . It is also rarely found in southern Scandinavia . In Austria the species is absent or rarely represented and potentially endangered. In Switzerland , it rarely occurs only in southwestern Switzerland.
Distribution in Germany
The small rock cress is rare in Germany . Except in the Saale / Unstrut area, you can still find them in a few places in Lower Franconia , on the Süntel in Lower Saxony and in the Palatinate .
Systematics and taxonomy
The genus Hornungia has often been combined with the genus Hutchinsia ( rock cress , steppe cress ). A synonym of this species is Hutchinsia petraea (L.) WT Aiton .
It was named after the pharmacist, botanist and entomologist Ernst Gottfried Hornung (1795–1862).
Species protection
Endangerment in Germany: Category 2: endangered
literature
- Henning Haeupler , Thomas Muer: picture atlas of the fern and flowering plants of Germany (= the fern and flowering plants of Germany. Volume 2). Published by the Federal Agency for Nature Conservation. Ulmer, Stuttgart 2000, ISBN 3-8001-3364-4 .
- Wolfgang Adler, Karl Oswald, Raimund Fischer: Excursion flora of Austria. Ed .: Manfred A. Fischer . Ulmer, Stuttgart / Vienna 1994, ISBN 3-8001-3461-6 .
- August Binz , Christian Heitz: School and excursion flora for Switzerland , Schwabe & Co. AG, Basel, 1986, ISBN 3-7965-0832-4
- Erich Oberdorfer : Plant-sociological excursion flora , Ulmer Verlag, Stuttgart, 1990, ISBN 3-8001-3454-3
- Christian August Friedrich Garcke : Illustrierte Flora , 1972, Paul Parey publishing house, ISBN 3-489-68034-0
Individual evidence
- ↑ a b Erich Oberdorfer : Plant-sociological excursion flora for Germany and neighboring areas . 8th edition. Verlag Eugen Ulmer, Stuttgart 2001, ISBN 3-8001-3131-5 . Page 451.
Web links
- Small rock cress. In: FloraWeb.de.
- Distribution map for Germany. In: Floraweb .
- Hornungia petraea (L.) Rchb. In: Info Flora , the national data and information center for Swiss flora . Retrieved October 26, 2015.
- Distribution in the northern hemisphere according to: Eric Hultén , Magnus Fries: Atlas of North European vascular plants 1986, ISBN 3-87429-263-0
- Thomas Meyer: Data sheet with identification key and photos at Flora-de: Flora von Deutschland (old name of the website: Flowers in Swabia )
