Abrus precatorius

Rosary pea

Nonnative to FloridaFlorida Noxious Weed ListFISC Category 1 Invasive

Species Overview

Native to: India and Asia 

The native range of rosary pea is India and parts of tropical Asia. It has been widely used throughout Florida's landscapes as an ornamental plant for many years. Rosary pea is highly toxic and can be fatal if ingested. In its native range, the roots are used to induce abortion and relieve abdominal discomfort. One of the most deadly plant toxins, abrin, is produced by rosary pea. Studies have shown that as little as 0.00015% of toxin per body weight will cause fatality in humans (a single seed). Birds appear to be unaffected by the deadly toxin as they readily disperse rosary pea seed. The seeds of this plant are so uniform in size and weight that they are used as standards in weight measurement as well as to make jewelry, including rosaries. 

Species Characteristics

  • Family: Fabaceae
  • Habit: high-climbing, twining or trailing woody vine with slender herbaceous branches
  • Leaves: alternate, petioled, and even-pinnately compound, 2-5 inches long, with 5 to 15 pairs of oval to oblong leaflets less than 1" long
  • Flowers: pea-like flowers are small, pale, and white to violet to pink, densely clustered in leaf axils
  • Fruit: the seed pod is oblong, flat and truncate shaped, roughly 1 1/2 - 2 inches long and curls back when it opens
  • Seeds: 3 to 8 shiny, hard, brilliant red seeds
  • Distribution in Florida: central and south

Impacts

Rosary pea is found throughout central and south Florida, and often invades undisturbed pinelands and hammocks. It also has a tendancy to invade distrurbed sites, such as pastures and roadsides. Though is lacks tendrils, rosary pea can grow over small trees and shrubs. It has a deep taproot, making it very difficult to remove. Fire encourages the growth of rosary pea.

Rosary pea is not recommended by UF/IFAS. Rosary pea is a prohibited plant according to the FDACS Florida Noxious Weed IndexThe UF/IFAS Assessment lists rosary pea as prohibited and FLEPPC lists it as a Category l invasive species due to its ability to invade and displace native plant communities.

Control Methods

Preventive Measures

Regular monitoring and removal of plants can prevent the spread and establishment of rosary pea. Programs to educate homeowners on proper plant identification will also reduce the spread of this species. Native alternatives to rosary pea for use in home landscaping or natural areas include leather flower (Clematis crispa) or Carolina jessamine (Gelsemium sempervirens).

Cultural/Physical

Hand-pulling and removal of entire plants, particularly the roots, is practical for small infestations. Remove seed pods if possible and pull seedlings. Fire provides only temporary control.

Mechanical

Aggressive tillage is an option and very effective, but impractical in many areas.

Biological

There are no known biological control agents for rosary pea.

Chemical

Timing of application is critical to effectiveness; with applications in the fall prior to seed set being the most effective. Site must be revisited several times to pull seedlings.

  • Cut-stump: Triclopyr is effective on large woody vines immediately after the vines are cut down
  • Foliar: 0.12–0.25% Milestone; 5% glyphosate product

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