Thursday, March 28, 2013

Content Highlights – Death cap (Amanita phalloides)

The death cap is one of the most poisonous mushrooms in the northern hemisphere. However, did you know that food prepared with a death cap is extremely tasty?

Amanita phalloides; this image is under CC-BY-NC-SA of Danish Mycological Society in Europeana

The death cap is medium sized mushroom, with cap 7-15 cm in diameter. It grows throughout the entire temperate zone of Europe, Asia and North Africa. It was carried (probably with tree seedlings) to North America and Australia. This mushroom grows from summer through fall in deciduous or mixed forests. The death cap is responsible for most mushroom poisonings, and even small doses can be very dangerous. Resistance to the poison varies among individuals, so specifying a fatal dose is difficult. The poison - amanitin, damages the liver and kidneys.

Amanita phalloides by František Šaržík from EOL

Initial symptoms occur 8 to 48 hours after ingestion. In this phase, the person experiences fatigue, stomach nausea, dizziness, headaches and feelings of cold, even freezing. The nausea intensifies, stomach aches occur, accompanied by strong retching and watery diarrhea, leading to dehydration, and eventual circulatory failure. This is usually the immediate cause of death in children. If the patient survives this phase, his condition appears to improve (usually the fourth day after ingestion). In the second phase, the kidneys fail, and sometimes the liver as well. Death usually occurs four to twelve days after ingestion. Treatment of death cap poisoning involving infusions with a high concentration of thioacetic acid was invented by the Czech doctor J. Herink.

Amantia from BHL

You can find more about death cap on BLE – Poisonous nature. Stay tuned to us!

Thursday, March 21, 2013

Content Highlights - Deadly nightshade (Atropa belladonna)

Look at one of the most poisonous plants in Europe - deadly nightshade (Atropa belladonna). Did you know that in the early and middle ages, women of all ages rubbed belladonna juice into their eyes to make them large and beautiful, from which also comes the species name of the plant (bella donna = beautiful woman)?

Atropa belladonna from Europeana (image is under CC-BY-SA, from Biologiezentrum der Oberoesterreichen Landesmuseen)

Deadly nightshade is massive 50-180 cm tall shrub with dark purple bell-shaped flowers. The pods are shiny black berries the size of a cherry. Nightshade grows in well-lit forests all over Europe, diminishing northwards. This plant belongs to the Solenaceae family, as do the potato and tomato. All parts of the plant are poisonous, and contain tropane alkaloids.

Oepn Up! content of Atropa belladonna on Europeana

Nightshade's principal danger lies in that its berries are very pretty and look edible, have a pleasantly sweet taste, and are at eye level for children, to whom they look like overripe cherries. Two to four berries are a fatal dose for a child, an adult needs ten to twenty. The most poisonous part of the plant is the root, but the consumption of even a single leaf can be fatal for an adult. Symptoms are initially a red face, dry mouth, dilated pupils and quickened pulse; in later stages, heart arrhythmia, tremors, hallucinations, paranoia and cramping.

Atropa belladonna from BHL

This plant is widely used in medicine. Nightshade is an ingredient in atropine drops, used in ophthalmology, because atropine dilates the pupils. Extract from nightshade leaves is also used in analgesics to counteract cramps of smooth muscle tissue (antispasmodic). For more information see BLE Poisonous Nature. Stay tuned!

Thursday, March 14, 2013

Content Highlights – Woolly Mammoth (Mammuthus primigenius)

The winter is slowly ending; snow is melting and we dedicate a short piece to one of the largest mammals from the last Ice Age – the woolly mammoth (Mammuthus primigenius).

The mandible of woolly mammoth from Europeana

During the late Pleistocene, Mammuthus primigenius occupied the grassland areas of Eurasia and North America. This mammal, closely related to today’s Indian elephant, grew to 4.5 m and could weigh up to 4000 kg. It fed mainly on different sorts of grass. The hair of Mammuthus primigenius was up to 60 cm long and its color ranged from tawny through brown to black. In addition to bones, scientists have recovered much information about Mammuthus primigenius from frozen specimens in Siberian permafrost.

As a matter of fact, it is not true that all Woolly Mammoths were large animals. The dwarf subspecies of Mammuthus primigenius grew only to 1.8 m in height. This small chap occupied Wrangel Island from approximately 10,000 to 2,000 years BC! So these dwarf mammoths lived during the times of building the Egyptian pyramids.

Collection of bones of woolly mammoths from Europeana

The Europeana portal contains much information about woolly mammoths, including many images of OpenUp! content. For example, the beautiful mandible (above) is stored in the Museum of Geology, University of Tartu. It was collected in 1840 by Herr von Mierzerjewski in Poland, near Bug River. This sample measures 50x50 cm and weighs 16.6 kg.

The mammoth from BHL

If you are interested in these prehistoric creatures, you can find great collections on Europeana portal. Stay tuned!