Calabar bean
Calabar bean ( Physostigma venenosum )
The Calabar bean also ordeal bean ( Physostigma venenosum ) is a species in the subfamily of the Fabaceae ( Faboideae ). It is native to West Africa and is known mainly due to their toxicity.
- 7.1 Literature
- 7.2 Notes and references
Description
Kalabarbohnen perennial climbing plant with verholzendem strain ( lianas ), which reach a length of up to 15 meters. The trunk diameter of up to 5 centimeters.
The leaves are unpaired, feathery three parts. The leaf blades are ovate and pointed.
The axillary, stalked, drooping racemose inflorescences are up to 2.5 inches long. The Blütenstandsrhachis is littered with nodule -like nodes. The bracts fall off at an early stage of anthesis.
The typical butterfly flowers are rolled up in a spiral manner. Boat and wings of the flowers are dark purple. The flag is folded, bent back and lighter in color. Boat and wings are almost completely obscured by the flag. The boat is twisted spirally at the top.
The stamp has a stalked ovary with a slim pen that is bent with the boat. He is hairy beard -like on the inside. The only carpel is stalked. The stylus has a dilated, triangular, wing-like extension behind the scar.
The thick brown legumes are up to 15 centimeters long. Each fruit contains two or three seeds. The deep chocolate brown seeds are slightly kidney-shaped with rounded ends and a length of about 2.5 centimeters. The surface is rough but at least partly glossy. At the point where the seed was grown in the placenta, a scar remains.
The fruits float and spread the diasporas is so hydro choir instead.
Dissemination
The Calabar bean grows on riverbanks, often even in shallow water in the tropical rain forest, where she climbs on trees.
It is in a small area on the Gulf of Guinea and in the delta of the Calabar River, in the state of Cross River in Nigeria, endemic.
Neophyte deposits are found in India and Brazil.
In the seeds
The seeds of the Calabar bean contain starch (48 percent), mucilages, proteins ( 23 percent), fats ( 2.3 percent ) and salt ( potash).
The seeds contain slightly more than 1 percent of alkaloids. Significantly, the indole alkaloid physostigmine, which was isolated by Julius Jobst and Hesse Oswald in 1864 from a Calabar bean. A year later, in 1865 isolated Amedee Vee and Leven Manuel the substance regardless of eserine and called him.
Erich Ludwig Harnack and Witkowski discovered in 1876, a second alkaloid in the Calabar bean and called it Calabrin. Calabrin is not unlike the strychnine.
These two toxins are found exclusively in the seeds of the plant and there almost exclusively in the cotyledons. All other parts of the plant are poisonous.
Use
Extracts from the Calabar bean were used in the past in ophthalmology as miotic for pupillary constriction. In European medicine it is first mentioned in 1855 as a miotic. Also, physostigmine is an effective antidote for atropine poisoning.
Kalabarbohnen were used as a cholinergic ( parasympathomimetic ), as physostigmine, acts as an acetylcholinesterase inhibitor.
Cultural History
The first Europeans who came to Kalabarbohnen, was in 1846 William Freeman Daniell. Previously, the beans were guarded by the natives as secret and not disclosed to whites. Had the respective king or tribal leader 's monopoly on the beans. Wild specimens were pulled out and the beans were very expensive.
The beans were used but apparently also traded mainly by the Efik, as reported by similar rituals with Kalabarbohnen also from northern Nigera. The bean was suspected criminals administered to bring about an ordeal. About half of the people died very quickly to the seed, which has been considered as evidence of the guilt of that. The delinquent, however, had passed, choked the seeds out and survived, he was considered innocent. He did not vomit, only had diarrhea and survived, he was considered guilty and was sold as a slave.
The mere threat of this form of God's judgment was considered so daunting that defendants often, even in innocence, rather stood and redress rendered.
Similar rituals are known from Madagascar, where the poisonous nut fruit of Tanghinia venenata was used. In Sierra Leone there was a similar rite. Here a poisonous tea made from the bark of Erythrophlaeum guineense was used.
Another use of the Kalabarbohnen lay in a form of a duel. Here, the seed was divided into two halves and eaten by both subscribers. However, not infrequently died both counterparties.
System
Physostigma venenosum was first described in 1860 by John Hutton Balfour. It is the type species of the genus Physostigma.
Etymology
The scientific name of the species venenosum comes from Latin and means poisonous. The genus name is from ancient Greek Physostigma φυσα ( Physa ) = bladder and στιγμα ( stigma ) = scar composed of what is due to the wing-like extension behind the scar, which is in some species of the genus bubble -like pronounced.
The trivial name Calabar bean has its name from its location at the Calabar River. The species is also called God's judgment bean, which is due to the historical and cultural rituals.
Swell
The information in the Description section originate, unless otherwise specified, the source is:. Felter & Lloyd Lloyd in 1897 and 1898 was used for the chapter in the seeds unless otherwise indicated Felter & Lloyd 1898 as the main source. Was for the chapter cultural history again, unless otherwise noted, Lloyd used 1897.