Today we went on a trip to Mamiku Gardens, on the south-east coast of St Lucia. We hired a taxi with a lovely driver called Charleson, who explained the local sights and stories as we went. It was a great day out.
Abrus precatorius, commonly known as jequirity bean or rosary pea, is a herbaceous flowering plant in the bean family Fabaceae. It is a slender, perennial climber with long, pinnate-leafleted leaves that twines around trees, shrubs, and hedges.
The plant is best known for its seeds, which are used as beads and in percussion instruments, and which are toxic because of the presence of abrin. Ingestion of a single seed, well chewed, can be fatal to both adults and children. The plant is native to Asia and Australia. It has a tendency to become weedy and invasive where it has been introduced.
Abrus precatorius is commonly known as jequirity, Crab's eye, or rosary pea, paternoster pea, love pea, precatory pea or bean, prayer bead, John Crow Bead, coral bead, red-bead vine, country licorice, Indian licorice, wild licorice, Jamaica wild licorice, olinda (In Sri Lanka/Sinhala), kundumani (in Tamil), coondrimany, gidee gidee, Jumbie bead, ratti / rettee / retty, or weather plant.
In Africa, Abrus precatorius is known as Ojuologbo (Yoruba), Oto-berebere (Igbo), Idonzakara (Hausa) and Nneminua (Ib) in southwestern Nigeria and obirekuaiura in Ghana.
The toxin abrin is a dimer consisting of two protein subunits, termed A and B. The B chain facilitates abrin's entry into a cell by bonding to certain transport proteins on cell membranes, which then transport the toxin into the cell. Once inside the cell, the A chain prevents protein synthesis by inactivating the 28S RNA of the ribosome. One molecule of abrin will inactivate up to 1,500 ribosomes per second.
Symptoms are identical to those of ricin, except abrin is more toxic by almost two orders of magnitude; the fatal dose of abrin is approximately 1/75 that of the fatal dose of ricin (though the abrin in ingested seeds may be absorbed much more slowly than the ricin in Ricinus communis even if the seeds are chewed and the coat penetrated, allowing time for successful rescue efforts in at least some cases.) Ingesting intact seeds may result in no clinical findings, as they can pass undigested through the gastrointestinal tract because of their hard shell.
This plant is also poisonous to horses.
Symptoms of poisoning include nausea, vomiting, convulsions, liver failure, and death, usually after several days.
The seeds of Abrus precatorius are much valued in native jewelry for their bright colouration. Most beans are black and red, reminiscent of a ladybug, though other colours exist. Jewelry-making with jequirity seeds is rumoured to be somewhat hazardous. There are persistent reports that the workers who pierce the seeds in order to thread them can suffer poisoning or even death from a pinprick, but there seems to be little evidence. An online search found 265 scientific papers referring to Abrus precatorius, but not one of them dealt with occupational poisoning.
In Trinidad in the West Indies the brightly coloured seeds are strung into bracelets and worn around the wrist or ankle to ward off jumbies or evil spirits and "mal-yeux" - the evil eye. The Tamils use Abrus seeds of different colours. The red variety with black eye is the most common, but there are black, white and green varieties as well.
I have a couple of necklaces made from these beads which I used to play with as a child. And here I still am!
