Emex spinosa
Stechampfer ( Emex spinosa)
The Stechampfer ( Emex spinosa) is one of two species in the genus Stechampfer ( Emex ). Your home is the Mediterranean region but is now widely used as invasive plant beyond.
Description
The Stechampfer is an annual herbaceous plant, the plant height between 30 and 60, rarely reaching up to 80 centimeters. The ascending to erect stems is reddish in color at its base and branches at the bottom.
The alternate on the stem arranged leaves are bald. The Ochrea is bald. The petiole has a length of 2 to 29 cm. The simple leaf blade is 3-13 cm long and 1.1 up to 12 cm wide, ovate to ovate -oblong or triangular, usually clipped to a sweetheart Spreitengrund and pointed to blunt Spreitenspitze.
The Stechampfer is monoecious getrenntgeschlechtig ( monoecious ) and blooms all year in North America. In a total inflorescence are each about a Ochrea tufts with one to eight male or two to seven female flowers together. The unisexual flowers have a diameter between 5 and 6 mm. The bloom are narrow oblong to lanceolate wrong with the male flowers at a length of 1.5 to 2 mm. In the female flowers the three outer bracts are ovate to oblong and the three inner linear- lanceolate with pointed top.
The durable bracts surround the fruit and then the three outer 4-6 mm and the inner three are 5-6 mm long, they are verdornt and spread to bent back. The three-sided glossy achenes are 4 to 5 mm long and 2-3 mm wide.
The chromosome number is 2n = 20
Dissemination
The original distribution area of Stechampfers located in the Mediterranean and the Orient.
In areas with a similar climate to the Stechampfer has spread invasively. In the United States it is found in California, Texas, Florida, New Jersey and Massachusetts, where it is colloquially called 'lesser jack ". In addition, it has spread to Africa in Kenya, Mauritius and the Canary Islands and in India, Hawaii and Australia. The deposits in South America ( Argentina, Chile, Uruguay, and Ecuador and Peru ) are based on introduction.
The Stechampfer multiplies very rapidly, displacing native species by overgrowth. He is classified as a noxious weed ( " noxious weed" ) in the United States and is systematically combated.
Taxonomy
The first publication of this kind took place in 1753 by Carl Linnaeus in Species Plantarum under the basionym Rumex spinosus L. Francisco Campderá put it in 1819 under the name Emex spinosa than it was then only species in the genus newly described in the same publication Emex.
Swell
- Craig C. Freeman: Emex. In: Flora of North America Editorial Committee ( eds.): Flora of North America North of Mexico. Volume 5: Magnoliophyta: Caryophyllidae, part 2, Oxford University Press, New York / Oxford et al 2005, ISBN 0-19-522211-3, p 488 (online, limited preview on Google Book Search ). (Sections Description and systematics).
- Mohammad Qaiser: Flora of Pakistan 205: Polygonaceae. University of Karachi, Department of Botany / Missouri Botanical Press, Karachi / St. Louis 2001, ISBN 1-930723-08-3, online. ( Description section )