Rosary Pea, Precatory Bean, Abrus precatorius
While camping at Oscar Scherer State Park last fall, our campsite had a beautiful climbing vine at the end of it. When I pointed it out, everyone in my family said, "Is that a fern?" Well, it turns out that it is a non-native, naturalized vine, that is listed on the Florida Invasive Plant List as a Category I.
This particular vine was about 15 feet tall, it climbed from the ground into an oak tree very dramatically. It had 4 or 5 stems which were intertwined (growing up an older vine?) and many, many clumps of pods that looked like this one. I regret not having my camera for a photo of it!
Historically it was cultivated for ornamental value. Both the vines and beans are attractive. The beans were formerly used to make jewelry, particularly necklaces, hence the name Rosary Pea.
It is also known to be one of the most toxic plants on the planet, even more toxic than castor bean, because it contains a chemical called abrin, which halts all cellular protein synthesis. That sounds like a relatively painless way to go, is it any wonder that Rosary Pea had been used historically as a suicide agent? Most poisoning occurs unintentionally when children and animals eat the beans.
It was featured in this National Institute of Health paper about death by mail-order. Among the natural toxins in this study, it is ranked fourth, while castor bean came in at a lowly twelve.
Why are beans so toxic? Why are brightly colored things so poisonous?