Carolina nightshade
| Carolina nightshade | ||||||||||||
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Carolina nightshade ( Solanum carolinnse ) |
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| Solanum carolinense | ||||||||||||
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The Carolina nightshade ( Solanum carolinense ), also called horse nettle , is a species of plant from the nightshade family (Solanaceae) native to the southeastern USA . It has been introduced into many countries from the tropics to temperate areas and is considered an invasive plant .
features
The Carolina nightshade is a perennial , herbaceous plant . It is only weakly branched at the base. Depending on the place of growth, it reaches heights of between 20 and 120 centimeters. The upright stems, like the leaves , are covered with hard, yellow spines . The leaves are alternate, four to 14 centimeters long and lobed. Stems and leaves have four- to eight-armed star hairs on the surface.
The root system is characteristically extensive. It consists of a taproot , which can reach 240 centimeters deep, and horizontally growing roots that are several meters long and 45 centimeters deep in the ground. The plants can regenerate very well from root buds that are located on the horizontal roots. New plants can grow from separated, individual pieces of root within a few weeks.
The inflorescences arise from the side and are, as is often the case with the nightshade family, partly fused with the stem axis ( concealment ). The radial symmetry flowers have five fused, light blue, rarely white petals . The five stamens incline to form a cone. They have long, yellow anthers and release the pollen through pores at the tip of the anthers.
The fruits are yellow to yellow-orange berries that are round and eight to 20 millimeters in size. In terms of ingredients, they contain large amounts of α- solasonine and α- solamarine , furthermore solanine alkaloids and saponins . The high alkaloid content has an anti-fungal effect and prevents the fruits from breaking down, which means they remain available as diaspores for a long time. The fruits contain 40 to 170 (rarely only up to 13) seeds . The average number of seeds per berry is 86.
The germination rate of the seeds is high. They remain viable for three years and can still germinate at a depth of 10 centimeters. The seeds need daily temperature fluctuations between 20 and 30 ° C for germination. The seedlings initially form an extensive root system.
The number of chromosomes is 2n = 24.
Spread
The species spreads vegetatively through root shoots and generatively through seeds. With its meter-long roots, from which new shoots emerge, a single plant can colonize large areas. Even pieces of root two centimeters long and 3.5 millimeters in diameter showed a regeneration rate of 100%. 10 cm long pieces of root can form plants if they are 60 cm deep in the ground. The spread by agricultural machines, which split the roots and drag them along with them, is the most important mechanism of propagation of the species in agricultural areas. It is also spread through contaminated seeds.
The fruits are consumed by animals and so the seeds are spread ( endozoochory ). The most important consumers are birds, as well as small mammals. Grazing animals avoid the plants because of the spines.
distribution
The original range of the species are the US states on the Gulf of Mexico. In northern Mexico ( Sonora , Tamaulipas and Nuevo León ), in 31 states of the USA and in southern Canada it is now considered naturalized. The species has a high tendency to spread. Beyond North America, it was introduced into the following countries: Bangladesh , India , Nepal , Japan , Australia , New Zealand , Haiti , Brazil , Georgia and Turkey . In Europe she is known from Croatia , France , Germany , the Netherlands , England , Norway and Austria . In Switzerland, it was included in the black list of invasive neophytes due to its potential for spreading and the damage in the areas of biodiversity , health and economy .
The natural locations are the deciduous deciduous forests. As an invasive plant, it grows in fields, gardens, meadows, fallow land and along roadsides. In the US, it is rated as one of the top 10 most problematic weeds. It grows preferentially in fields or plantations of peanuts , tea ( Camellia sinensis ), tomatoes , potatoes , corn , soybeans , garden beans ( Phaseolus vulgaris ), garden strawberries ( Fragaria ananassa ), alfalfa ( Medicago sativa ), and various sweet grasses: Cynodon dactylon , common ball-grass ( Dactylis glomerata ), reed-grass ( Phalaris arundinacea ), meadow bluegrass ( Poa pratensis ).
Systematics
The Carolina nightshade belongs to the subgenus Leptostemonum of the genus nightshade ( Solanum ). Its closest relatives are the two South American species Solanum conditum and Solanum comptum .
use
Due to its high alkaloid content, the Carolina nightshade is used in naturopathy for a whole range of indications: asthma , bronchitis , convulsions, epilepsy and tetanus . It is also known to be used as a sedative, pain reliever, aphrodisiac , anthelmintic and as an insecticide .
literature
- Roland Karl Eberwein, Thomas Litscher: Solanum carolinense L. (Solanaceae), a dangerous new citizen in Austria. In: Rudolfinum. Yearbook of the State Museum of Carinthia 2005. Klagenfurt 2007, ISBN 978-3-900575-38-0 , pp. 325–330 ( PDF on ZOBODAT ).
- S. Miller: Pest fact sheet Solanum carolinense L. NAPPO North American Plant Protection Organization, Ottawa 2003 ( PDF , nappo.org).
Individual evidence
- ↑ Solanum carolinense at Tropicos.org. In: IPCN Chromosome Reports . Missouri Botanical Garden, St. Louis
- ^ Federal Office for the Environment FOEN: Invasive Alien Species . ( admin.ch [accessed on August 6, 2019]).
- ↑ S. Buholzer, M. Nobis, N. Schoenenberger, S. Rometsch: List of the alien invasive plants of Switzerland . Ed .: Infoflora. ( infoflora.ch [accessed on August 6, 2019]).
- ^ S. Miller, 2003.
