Rosary pea (Abrus precatorius) is a slender, high-climbing, twining or trailing woody vine with slender herbaceous branches. It is well known for its distinctive red and black, highly toxic seeds, that are commonly used for making jewelry for tourists. A. precatorius is found in tropical and subtropical areas worldwide. It has fern-like elliptical leaflets that grow in pairs along the leaf stalk, and white to lilac-pink flowers that bloom in the summer. A. precatorius produces flat brown seedpods with oval seeds which vary in color from black, red, orange or white with a black spot, giving the plant another common name of crab's eyes.
Toxic components A. precatorius contains abrin (a type of protein toxin that is related to ricin) within the hard, water-impermeable coating of it's distinctive red and black patterned seeds. The toxin is not released unless the seed is chewed and digested or the seed coat is otherwise broken. Once released, protein toxins (toxalbumins) inhibit the function of ribosomes, which are the subcellular organelle responsible for protein synthesis. Once the toxins are absorbed into the blood stream, rapid multi-system organ failure follows close behind.
MECHANICAL: Hand-pulling and removal of entire plants, particularly the roots, is practical for small infestations. Triclopyr is effective as a cut-stump treatment on large woody vines immediately after the vines are cut down.
CHEMICAL: Triclopyr amine or glyphosate can be applied to the foliage at 3-5% or 1-3%, respectively. Timing of application is critical to effectiveness; with applications in the fall prior to seed set being the most effective.
FIRE CONTROL: It's roots grow very deeply onto the ground and are very difficult to remove. Fire encourages the growth of rosary pea.