Austrian milkweed
| Austrian milkweed | ||||||||||||
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Austrian Spurge ( Euphorbia austriaca ) |
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| Euphorbia austriaca | ||||||||||||
| A. Core. |
The Austrian spurge ( Euphorbia austriaca ) is a species of the family of the spurge family (Euphorbiaceae). It is an Austrian endemic in the north-eastern limestone Alps of the montane to subalpine altitude range .
description
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This perennial herbaceous plant reaches heights of between 50 and 80 centimeters. A thick-rolled rhizome serves as a storage and persistence organ . Long-creeping underground runners ensure vegetative reproduction . The plant has a caustic, sharp, poisonous latex.
The upright growing stem can be slightly hairy or hairless. The short stalked leaves have no stipules. They are arranged in alternate leaf positions along the stem axis . The blade of the middle and upper stem leaves shows a narrow-elliptical to oblong shape . Their length measures seven to ten centimeters, the width is between 2 and 3.5 centimeters. The upper side of the leaf is bare, on the underside of the leaf a soft hairy hairiness is usually formed. The leaf margin can be designed with entire margins or finely sawn. The intense yellow-green coloring of the leaves in the upper section of the stem axis is striking.
The individual flowers are arranged in cyathia, which are typical for the species of the genus milkweed . These combine to form a pleiochasium , an umbel-shaped thyrse. Lateral partial inflorescences arise from the uppermost leaf axils , which do not protrude beyond the five-pointed terminal umbel. The bracts of the inflorescence rays are ovate-round and yellow-green in color. The bracts of the single inflorescences have an obovate or ovoid shape and are also yellow-green in color. The 4 to 5 millimeter long envelope cup of the cyathium is formed from five bracts that have grown together . On its edge there are four extra-floral, transversely oval , blunt nectar glands with oval appendages without crooks. The cyathium contains only unisexual flowers, which also have no flower envelope . In the center is the female flower, which consists of an upper, triple, stalked ovary . It changes into three styles with two scars each . In the further development the ovary elongates and then hangs on one side beyond the envelope. The male flowers are inserted in the axils of the bracts and consist of a single stalked stamen with two anthers . The gently furrowed capsule fruit is hairy with long hairs. It becomes about 4 millimeters long, its surface can be smooth or slightly warty. The smooth seeds develop a length between 2.3 and 2.5 millimeters. They are oval-spherical in shape.
The flowering period extends from May to July.
The number of chromosomes is 2n = 20.
distribution
The Austrian milkweed is an Austrian endemic to the north-eastern Limestone Alps, from the Ötscher region to the Salzkammergut . It is scattered in the federal states of Lower and Upper Austria, Styria and Salzburg (very rarely) to be found.
It preferably grows in fresh, lime-rich and sparse forests, tall herbaceous meadows and fatty willows from the montane to subalpine altitude .
swell
literature
- Manfred A. Fischer , Wolfgang Adler, Karl Oswald: Excursion flora for Austria, Liechtenstein and South Tyrol. 2nd, improved and enlarged edition. State of Upper Austria, Biology Center of the Upper Austrian State Museums, Linz 2005, ISBN 3-85474-140-5 .
- Euphorbia In: Gustav Hegi : Illustrated flora of Central Europe. 1st ed. Volume V (1), Carl Hanser, Munich, p. 134 ff.
Individual evidence
- ↑ Kalkalpen National Park: Austria-Wolfsmilch , accessed on June 18, 2018.
- ↑ Dieter Heß: Systematic Botany ( UTB. Volume 2673). Eugen Ulmer, Stuttgart (Hohenheim) 2005, ISBN 3-8252-2673-5 , p. 147 ff.
- ^ Euphorbia austriaca at Tropicos.org. In: IPCN Chromosome Reports . Missouri Botanical Garden, St. Louis
