This plant is a very aggressive grower, with spines or thorns along the stems, which makes them more difficult to remove. The leaves are large, with compound alternate leaflets. This twining perennial can range from 12 to 40 feet (4 to 12 meters) in size, and is listed as an invasive climber. The pink and white blooms, which appear in summer and early fall, are vaguely reminiscent of sweet peas, also in the legume family, though they are larger. They are best known for the brilliant seeds that emerge from the dried pods, however. They are most commonly a dazzling scarlet with a black tip at one end; other colors, including white, are less prevalent. When I first saw them, my initial impression was that they looked like ladybugs, minus the spots! They self-seed readily, and can become invasive in areas with a compatible climate. Dave's Garden members in Florida have commented on their aggressive nature, and note that they smother and kill desirable and native plants, and are very difficult to eradicate. For this reason, they are not recommended for the home garden.
One of the most popular uses of the colorful beans is in jewelry and rosaries, lending the bean another of its common names, rosary pea. It is also commonly used in bracelets worn around the wrist or ankle in the West Indies to ward off the "evil eye." This tradition of using the beans as beads for jewelry seems to lead to the most accidental poisonings. As I read more about these petite peas, I learned that jewelry makers have died from pricking their fingers while manually drilling through the tough hulls on the outside of the beans, or from getting the highly toxic powder on their fingers and ingesting it or rubbing it into their eyes. There is also a serious risk that unsuspecting children (and even adults) will mouth the colorful beads or pull them loose from the jewelry, then chew or swallow them.
Reportedly, if the tough husks are intact, the bean can pass through the digestive system intact without harming the person who swallowed it. If it is chewed, cracked, or damaged from drilling or wear, however, it releases abrin, one of the most potent poisons in the plant world. Even one bean contains enough abrin to kill an adult, and the prognosis for those who have ingested it is not good. They also pose a danger to those with livestock and pets, as animals that browse on the plant can ingest the seeds. I stumbled across several reports of horses dying from consuming these poisonous plants.
People may be familiar with the poisonous effects of ricin, found in castor beans. According to the Centers for Disease Control (CDC), however, jequirity beans are considerably more dangerous. The Wikipedia article asserted that they are 75 times more toxic than ricin, though no source was cited to corroborate this statistic. Abrin can kill with a circulating amount of less than 3 micrograms. The initial symptoms, which may not show up for several days after ingestion, may be mistaken for other common gastrointestinal complaints, as they include vomiting, diarrhea, and abdominal pain. Within a short span of time, however, the person or animal will experience sudden weakness, renal failure, and possible hepatotoxicity, which may rapidly progress to succumbing to shock and death. Eye contact may lead to severe irritation and blindness.
The prognosis is fairly bleak for humans and animals alike. The veterinary entry from Perdue University warns that affected animals are likely to die, even with care. Do not induce vomiting in humans or animals, except under supervision of a medical professional, and even then only within the first hour after ingestion, for fear of worsening the damage to the gastrointestinal tract. There is no known antidote for abrin. The only treatment is to offer supportive medical care to counteract the effects of the poison.
Worldwide, other cultures have used the jequirity bean in a wide range of ways. In India, for example, the remarkable consistency of size was noted, and it was used as a weight of measure, the Ratti, which is equal to 0.12125 gram. In other areas, jequirity beans are popular as a noise-maker in instruments like maracas. This is another use with great potential for breaking the protective husk and exposing the dangerous inner parts of the bean. If an older maraca is broken or opened, the dust and pieces of shattered beans could be released, and accidentally inhaled or ingested. In China, they are known as "mutual love beads" and are a traditional token of fidelity.
Not surprisingly, the beans have been put to much less wholesome use. Since the toxin is so potent, and requires a fairly small dose, it has been used as a poison. The Centers for Disease Control in the United States have put together a treatment plan, in the event that someone develops a way to use it as a biological weapon, similar to how some assassins and terrorist groups have used ricin from the castor bean plant.
Some cultures even find culinary and medicinal value in these beans. Reportedly, the toxins are destroyed when the beans are boiled, though I personally wouldn't take the risk and try consuming them. They have been used in Siddha medicine for centuries, where the toxic seeds are boiled in milk to denature the proteins, and then dried, and used for purificiation purposes. The seeds are also used in Indian medicine for a wide range of complaints. Teas are also made with the leaves, which contain less concentrated amounts of abrin, to treat fevers, coughs and colds.
I was concerned, as I did my research, to find some sources online selling the seeds for these plants, with no note of their extreme toxicity. Some even suggested scarification of the seeds prior to planting, which would definitely expose the innocent purchaser to risk of accidental poisoning. Anything that compromises the tough outer hull of the seed is unwise.
Disclaimer: I do not recommend that you plant or even handle these seeds, or attempt to use them for jewelry, medical purposes, or any other purposes. If you choose to do so, it is at your own risk.
Thumbnail image of peas in pod: Dinesh Valke, via Wikimedia Commons
Botanical Drawing: Kohler Medizinal Pflanzen, via Wikimedia Commons
Ball Jar of Jequirity Peas: Jennifer White, used with permission
Leaves: Vietnam Plants, via Flickr Creative Commons
Abrus precatorius blooms: J. M. Garg, via Wikimedia Commons
Handful of Jequirity Peas: eyeweed, via Flickr Creative Commons