Lysichiton americanus

Skunk cabbage ( Lysichiton americanus)

The American skunk cabbage ( Lysichiton americanus), also American Riesenaronstab, Stinking Willie, Yellow bill Kalla or simply called Skunk Cabbage, is a species of the genus certificate Kalla ( Lysichiton ) within the family Araceae ( Araceae ).

• 5.1 Notes and references

Description

Vegetative characteristics

The American skunk cabbage grows as a deciduous, perennial herbaceous plant. It is obtained as a vertical rhizome outlasting the length of 30 cm or more and a diameter of 2.5 to 5 cm. The white roots are contractile.

The undergraduate, upright, deciduous leaves are divided into petiole and leaf blade. The thickness petiole has a length of 5 to 40 cm. The simple, leathery leaf blade ends acute to obtuse, has a wedge-shaped to almost truncated base and a length of 70 cm. The median nerve passes into the petiole. The leaves unfold only after the flowering period.

Generative features

The flowering time is in the late winter to spring. The typical Arum inflorescence has no inflorescence stem. Inflorescences of the American skunk cabbage (hence the common name ) have a bad, indoloiden odor, which is even more noticeable in old herbarium material; with its unpleasant odor to humans they attract insects for pollination to. The inflorescence consists of the spathe ( single bract ) and spadix (piston). The boat-shaped spathe surrounds the piston initially completely, the upper portion opens during the heyday far, only the lower area around the piston stem remains completely closed; wilting shortly after flowering of the individual flowers. The 4 to 12 (up to 14 ) cm long piston is initially shorter than the spathe, but since its beginning later 8 to 25 cm long stem grows to seed maturity is the piston after a while on the spathe addition. A flask contains numerous small flowers. The hermaphrodite flowers are cruciform. There are four yellow- green bracts present. There are four fertile stamens present. The one - or two-chamber usually ovary contains each chamber one to two ovules.

The elongated egg-shaped inflorescence have a length of 4 to 15 cm and a diameter of 1.5 to 4 cm. The berries contain one to four seeds. Can occur on any flask about 300 to 650 seeds. The gray - brown to red- brown seeds are (3 to ) usually 5 to 11 mm in size.

The chromosome number is 2n = 28

Occurrence

The American skunk cabbage is originally native to the North American continent in the Canadian and U.S. states of Alaska and British Columbia, Idaho, Montana, Oregon, Washington and California. It grows in swamps, wet woods, along streams and other somewhat moist areas at altitudes 0-1400 meters.

The American skunk cabbage is one of the few arum family ( Araceae ) that occur in the climate of the temperate zone, and settled in particular marsh and wetlands on acid soils, because of its shade tolerance mainly in forests. The American skunk cabbage is in some parts of Europe a neophyte, for example, isolated in Switzerland and Norway. In Sweden it is more common and regularly used in the UK and Ireland. The skunk cabbage was in some moist forests of the Taunus located northwest of Frankfurt since the late 1970s by people, has established itself there and greatly increased. Meanwhile, some other points Fund, for example, in the western Ruhr area, in Dusseldorf, as well as on the lower Elbe in the field Stade were reported.

Skunk cabbage as an invasive plant

Lysichiton americanus spreads almost exclusively generative, but vegetative propagation is not excluded, since this type is very capable of regeneration.

The account of their size and the conspicuous inflorescence impressive style can cover large areas densely and other rare species of moist forests as peat mosses, liverworts or - to a lesser extent - Orchids displace ( bioinvasion ). However, it grows very slowly and can be up to 80 years old and a long-distance propagation has not been observed (all known occurrences are from Ansalbungen or gardens ), so that the American skunk cabbage in the group of the most fast growing invasive neophytes occupies a special role.

Wetlands are in Germany mostly ecologically particularly sensitive areas, often even nature reserves, so that a herbicide application is neither useful nor legally permissible. The complete removal of the plants along with the powerful rhizome is therefore the most effective method. Prevention, information and reporting of occurrences in nature conservation or forestry authorities shall contribute to prevent further spread.

System

The first description of Lysichiton americanus followed in 1931 by Eric Hultén and Harold St. John: The American species of Lysichitum, in Svensk Botanisk Tidskrift, 25, pp. 455

Swell

• Sue A. Thompson: Araceae in Flora of North America, Volume 22, 2000: Lysichiton americanus - Online. (Section Description, systematics and distribution )
• Characteristics of Internet handbook NeoFlora at FloraWeb.