Wednesday, July 4, 2012

Content Highlights – Abrus precatorius known as “Jequirity”

As the content from the OpenUp! project gradually grows on the Europeana portal, we are preparing selections of natural history content highlights for you.
This specimen is stored at Botanic Garden and Botanical Museum Berlin-Dahlem and the image is under the Creative Commons cc-by-sa 3.0 license. More information about the image use is under this link

Our first object is an interesting poisonous plant: Abrus precatorius. This herb commonly named Jequirity or Crab's Eye is widely distributed in the tropics today, mostly as an invasive weed. It is a perennial climbing legume up to 10 m high, with white to red coloured flowers and pinnate leaves. The leaves are consumed as a vegetable in central and east Africa. Well known are the bright red seeds with black top, used as beads for necklaces and other jewellery, as well as in percussion instruments. Due to the uniform weight of the seeds - nearly exactly 0,28 g - the seeds were also used for weighing gold and jewellery. The seeds contain a strong toxin, named abrin. Abrin inactivates protein synthesis in cells. A fatal dose of this poison is only 3 micrograms (µg), therefore one seed can be lethal for a human. In traditional medicine in Asia and Africa the purified and detoxified seeds are a medicine against diseases of the eye.

This displayed specimen is a so-called isotype of a special subspecies of Abrus precatorius which occurs in Africa, as the name of the subspecies, subsp. africanus, suggests.

Abrus precatorius specimen on Europeana portal

A type specimen is of outstanding value for the biologist: The scientific description of an organism is generally done for one individual of the species (or subspecies), which is usually prepared and stored in a natural history museum with international status. The scientific name is closely linked with this individual, called a holotype. In the case of our Abrus precatorius subsp. Africanus specimen, we received from the Kew herbarium a duplicate of the holotype, called an isotype.

More objects are coming, stay tuned!