Alyssum desertorum

Steppe alyssum ( Alyssum desertorum )

Quilting alyssum ( Alyssum desertorum ) is a species within the family of cruciferous plants ( Brassicaceae). It is particularly common in Eastern and Southeastern Europe and Western Asia.

• 5.1 Notes and references

Description

Vegetative characteristics

Quilting alyssum is an annual herbaceous plant, reaching heights of growth of mostly 10 to 20 centimeters. In the above-ground parts of plants Stern hairs are present, which have more than 10 rays in the vegetative area. The leaves are usually 7.5 - to 9 times as long as wide, hairy gray. The basal leaves are 2 to 15, sometimes up to 30 millimeters long and often fallen at flowering time. The stem is provided with simple, undivided and ganzrandigen stem leaves which are narrowed at the base of the stem or may be missing.

Generative features

The terminal, racemose inflorescence has no bracts. The hermaphrodite, radial symmetry flowers are cruciform with a double perianth. The four sepals are usually 1.5 to 1.8 millimeters long and too occupied to the top with two-to four-rayed stellate hairs, which are more than 0.7 millimeters long. At the time the fruit sepals are already dropped. The four ( pale ) yellow petals are all the same size and usually 2.3 to 2.6 millimeters long. The two outer stamens are broad at the base, the four inner have an appendage on. The stylus is usually between 0.5 and 0.7 millimeters long.

The roundish, flattened silicles is bare on the surface. In individuals outside Europe the fruits have some star hair with adjacent beams on. The smooth seeds are ovate with a length of about 1 mm and round winged.

Phenology and ecology

The flowering of this therophytes ranges in Central Europe from April to May

Quilting alyssum grows in Central Europe on sandy hills, grass courts and railway embankments in the colline level stage.

Occurrence and risk

Quilting alyssum occurs naturally in Central, Eastern and South-Eastern Europe, North Africa, West and Central Asia, Siberia, China, India, Pakistan and the Caucasus. As it is naturalized in Finland, Estonia and Latvia as well as in western Canada and the western and central United States.

In the German-speaking steppe stone herb is native only in Austria. Very rare occurrences are known from the Pannonian region of Lower Austria - in March and in the field Steinfeld - known. In Vienna, where it, inter alia, on the Türkenschanze in Waehring and in Floridsdorf still occurred frequently until the early 20th century, the steppes alyssum is extinct and applies throughout Austria as threatened with extinction.

Pictures

Indument on a fallen leaf.

Mature silicles.

Winged seeds.