Euphorbia helioscopia
Midsummer spurge
The solstice spurge ( Euphorbia helioscopia ) is a flowering plant in the genus Euphorbia (Euphorbia ) within the family of Euphorbiaceae ( Euphorbiaceae ). The name and the German botanical draw attention to the peculiarity of the way to align their inflorescences to the Sun ( heliotropism ).
Description
The solstice spurge is an annual herbaceous plant that reaches the stature heights of up to 40 centimeters, with most plants, however, only 10 to 20 cm high and remain unbranched or branch only slightly from the base. The cylindrical, up to about 3 mm thick stalk bears only a few wrong - ovate leaves that are up to about 2 cm long. Linear growth is terminated by a whorl of five leaves, on which the terminal inflorescence appears.
The inflorescence forms the largest part of the plant. He is a five-pointed Trugdolde, which is divided into three branches ( trichotom ). The bracts, which constitute the largest part of the leaves, are leaf-shaped, often slightly serrated and yellowish- green. Also yellowish- green are only about 1 mm cyathia. The cyathia first formed usually wear five, appearing on more branched inflorescence stems cyathia usually only four broadly ovate to almost circular nectar glands. The deeply lobed, insulated draft tube fruit capsule has a diameter of about 3 mm and stands out on a curved handle from the cyathium.
The entire growing season is about March to November, the flowering time between April and October. Towards the end of the growing season, the plants are often attacked by mildew. At least with the first ground frost they die.
Like all Euphorbia species is also this plant is very poisonous.
Ecology
The solstice spurge is usually a Therophyt.
The flowers bloom by a civilization effect now even in winter. The inflorescences show a photonasty that is, they face the sun. Pollination is mainly by flies. Bloom time is from April to October.
The three-piece schizocarps fall into 3 " cocci ", the explosively open by a shock mechanism and up to 2 m far away hurl the netzgrubigen seeds. The seeds are long-lived. Fruit ripening from July to October. It also finds that is, instead of apomixis the formation of seeds without fertilization.
Vegetative propagation is possible by root sprouts.
Occurrence
This species originates probably from the Mediterranean and spread during the Neolithic synanthropic of man ( archaeophyte ). The natural range of the species extends from North Africa over the whole of Europe and Asia via Iran and India to China and Japan. In North and South America are wild plants brought ( invasive plant).
The solstice spurge is spread in front of premolars weed corridors chopped fields or in gardens and vineyards. She prefers nitrogen -and base- rich, loose soil and shows clay and nutrient richness of. After Ellenberg it is a fresh pointer, a weak acid to weak base pointer, growing on nitrogen-rich sites and a Verbandscharakterart the Fumitory spurge companies ( Fumario - Euphorbion ).
Taxonomy
Euphorbia helioscopia was first published in 1753 by Carl Linnaeus in Species Plantarum.
Gallery
Typical plant: not or slightly branched from the base, a few leaves, fünfblättriger whorl relatively large, yellow - green inflorescence.
Typical branching pattern of the inflorescence.