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Publication #SP 37

 

Rosary Pea (Precatory Bean), Abrus precatorius L.1

David W. Hall, Vernon V. Vandiver and Brent A. Sellers2

Classification

Common Name: Rosary Pea (Precatory Bean)

Scientific Name: Abrus precatorius L.

Family: Leguminosae (Fabaceae), Bean Family

Seedling

The cotyledons are oval and the first true leaves are compound (Figure 1).

Figure 1. 

Seedling, Rosary Pea (Precatory Bean), Abrus precatorius L.


[Click thumbnail to enlarge.]

Mature Plant

This perennial, climbing vine is woody in southern Florida to somewhat herbaceous in central Florida (Figure 2). It branches freely and can reach a height of approximately 6.5 meters. The leaves are alternate,measuring 3.3-11.5 cm, and are compound, having 8-20 pairs of leaflets. The leaflets are oblong with rounded ends that come to a point and measure 0.3-2.1 cm in length and 2-8.2 mm wide. The purple, pink or white flowers are crowded on a stalk measuring 3-6 cm. The fruit, a flat, broad, rectangular pod, measures 2.3-4.0 cm in length. Each pod contains 3-5 seeds that are scarlet with a black spot at the point of attachment. The pod splits when dried, revealing the clinging seeds.

Figure 2. 

Mature plant, Rosary Pea (Precatory Bean), Abrus precatorius L.


[Click thumbnail to enlarge.]

History

The Greek word abrus means delicate and refers to the leaflets. Precatorius is Latin for "one who prays" and alludes to the use of the seeds for rosaries.

Habitat

This weed is established in ornamental plantings, landscapes, and waste grounds in southern and central Florida, the West Indies, Mexico and South America.

Biology

This plant is extremely toxic to cattle, horses and humans. Ingestion of only one seed can result in death.

Footnotes

1.

This document is an excerpt from Weeds in Florida, SP 37, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Publication date: May 1991. Revised: March 2006. Reviewed March 2009. Please visit the EDIS Website at http://edis.ifas.ufl.edu.

2.

David W. Hall, former extension botanist, Herbarium, Florida Museum of Natural History; Vernon V. Vandiver, associate professor emeritus, Agronomy Department; Brent A. Sellers, assistant professor, Agronomy Department, Range Cattle Research and Education Center--Ona, FL; Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Gainesville FL 32611.

The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other extension publications, contact your county Cooperative Extension service.

U.S. Department of Agriculture, Cooperative Extension Service, University of Florida, IFAS, Florida A. & M. University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Nick T. Place, Dean.