Beach milkweed
| Beach milkweed | ||||||||||||
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Beach Spurge ( Euphorbia paralias ) |
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| Euphorbia paralias | ||||||||||||
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The beach spurge or dunes spurge ( Euphorbia paralias ) is a species of the genus spurge ( Euphorbia ) in the family of the spurge family (Euphorbiaceae). The German trivial names indicate the peculiarity of the species, always growing near a beach and there mostly on dunes .
description
Vegetative characteristics
The beach milkweed is a perennial herbaceous plant and reaches heights of 20 to 70 centimeters. Over its thin, up to 1 meter long taproot it branches strongly from their base. The initially green and somewhat fleshy twigs turn reddish and woody over time . They usually grow upright, but can also lie down with rising shoot tips.
The numerous, upright and overlapping, blue-green leaves are elongated-elliptical near the base with a length of 10 to 30 millimeters and a width of 1 to 6 millimeters, and higher up shorter and ovoid.
Generative characteristics
The flowering period extends from May to September, depending on the location. The inflorescences appear terminally and laterally from the uppermost leaf axils as short, three- to six-pointed umbels . Their paired bracts are light green and oval to kidney-shaped. The nectar glands of the cyathia are yellow to orange, oval to kidney-shaped, on the outside with an irregular edge and two horns.
The three-chamber capsule fruits have a diameter of about 5 millimeters and a clearly grainy surface. The seeds are egg-shaped, smooth and have an appendage ( caruncula ).
Chromosome number
The number of chromosomes is 2n = 16, less often 22.
Possibility of confusion
Euphorbia paralias, which occurs in the Mediterranean region, is very similar in shape to Euphorbia pithyusa L. However, it is smaller and less branched, has smooth fruits and is not found in direct proximity to the beach.
ecology
Since the seeds are buoyant due to their fat content of around 40% and are resistant to seawater for a long time , spread by insects (mostly ants ) is also possible via the sea .
Occurrence
The main distribution area of the beach milkweed is in the Mediterranean area . To the east the distribution area extends to the Black Sea , to the west on the Atlantic coast from Morocco via France , Belgium and the Netherlands to the British Isles . The species is also found in the Canary Islands and Madeira. As a salt-loving plant ( halophyte ), it can always be found near the coast. Preferred locations are smaller dunes . Sometimes it penetrates into smooth sandy areas in the hinterland or directly on the beach, and sometimes into gravel areas.
literature
- Carl von Linné : Species Plantarum , 1st edition, 1, 1753, p. 458.
- Ingrid Schönfelder & Peter Schönfelder : Kosmos Atlas Mediterranean and Canary Islands flora. Stuttgart 2002, ISBN 3-440-09361-1
Individual evidence
- ↑ Euphorbia paralias at Tropicos.org. In: IPCN Chromosome Reports . Missouri Botanical Garden, St. Louis.
- ↑ Rafaël Govaerts (Ed.): Euphorbia paralias. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved April 21, 2020.
Web links
- Euphorbia paralias in the Netherlands (Dutch).
- Euphorbia paralias L., Zeewolfsmelk. Verspreidingsatlas Vaatplanten (Dutch).
- Euphorbia paralias in Spain (Spanish).
- Euphorbia paralias L .. Data sheet distributed in France on Tela Botanica (French)