Douglas Barbe, USDA ARS, Bugwood.org

Family: Zygophyllaceae (Creosote-Bush Family)

Synonym(s):

Duration: Perennial

Habit: Herb

Listed by:
Invasive Plant Atlas of the US: 1
Federal Noxious Weed: 0
TDA Noxious Weed: 0
TPWD Prohibited Exotic Species: 0

Description: Herbaceous perennial producing multiple shoots annually from a woody crown. Mature plants are globose and can reach a height of 50 cm. Mature stems are often decumbent resulting in a more prostrate, spreading habit. Leaves alternate, dark green, fleshy, and highly dissected. Flowers are showy white with 5 petals, green sepals and prominent yellow stamens borne on pedicels along the upper half of the stem. Seeds are medium-size and borne in a 2-celled or 4-celled green capsule that dries and burst open at maturity. Capable of reproducing by seed or vegetatively by lateral roots. The young seedlings are capable of growing during periods of extreme water deficits. This species appears to be drought tolerant, occurring in Saudi Arabia and the western Gobi desert that receives as little as 80 mm annual precipitation.

History: Peganum harmala is native to Africa, the Middle East, and southern Asia. This species has spread to North America, South Australia, and South Africa. It was initially introduced to North American at Deming, New Mexico in 1928. Generally, P. harmala inhabits regions characterized by hot summers, for example it is a co-dominant species in Central and Upper Jezira Plains of Iraq where the mean summer temperatures exceed 40°C.

Biology & Spread: African rue is extremely drought tolerant and undergoes robust and rapid vegetative growth when soil moisture is available. It is found in disturbed environments such as roadsides and fields in desert to semi-desert areas. Seeds and root fragments are readily transported by running water and different means of human-interaction, such as vehicles, railcars, and earth-moving equipment. these methods easily spread new plants along transportation corridors. Seeds can also stick to the feet, fur, or feathers of animals.

Ecological Threat: African rue is extremely drought tolerant and undergoes rapid vegetative growth when soil moisture is high, and it secretes allelopathic chemicals into the soil that reduce the growth of surrounding native plants. This weed is extremely toxic to cattle, sheep, horses, and humans; it contains at least four poisonous alkaloids. The seeds and fruit are the most toxic, followed by young leaves and mature leaves. Since fire can release its toxic chemicals, if any wildfires were to hit an area infested with African Rue there could be severe secondary impacts.

US Habitat: Disturbed areas such as roadsides, right-of-ways, and abandoned cultivated fields. Also found near livestock watering facilities and travel routes.

Distribution

US Nativity: Introduced to U.S.

Native Origin: Northern Africa, Middle East, and Southern Asia

US States: AZ, CA, MT, NM, NV, OR, TX, and WA

Resembles/Alternatives:

Management: DO NOT BURN. The toxicity of the plant is so high that the wood cannot be burned. The chemicals within the plant are released when burnt, causing the smoke to become toxic. In Afghanistan the smoke is used to fumigate and rid houses of bedbugs and lice.

African rue has a complex root system and it is extremely difficult to control the plant using only mechanical techniques. To obtain effective long-term control, it is best to use herbicide treatments alone or in combination with a physical method.

USE PESTICIDES WISELY: ALWAYS READ THE ENTIRE PESTICIDE LABEL CAREFULLY, FOLLOW ALL MIXING AND APPLICATION INSTRUCTIONS AND WEAR ALL RECOMMENDED PERSONAL PROTECTIVE GEAR AND CLOTHING. CONTACT YOUR STATE DEPARTMENT OF AGRICULTURE FOR ANY ADDITIONAL PESTICIDE USE REQUIREMENTS, RESTRICTIONS OR RECOMMENDATIONS. MENTION OF PESTICIDE PRODUCTS ON THIS WEB SITE DOES NOT CONSTITUTE ENDORSEMENT OF ANY MATERIAL.

Listing Source

Texas Department ofAgriculture Noxious Plant List
Texas Parks and Wildlife Department Prohibited Exotic Species
Invaders Program
Federal Noxious Weed
Union of Concerned Scientists
United States Forest Service Southern Research Station

Text References

Abbott, L.B., T.B. Bettmann, and T.M. Sterling. 2008. Physiology and Recovery of African Rue (Peganum harmala) seedlings under water-deficient stress. Weed Science 56:52-57.

Abbott, L. B. and T.M. Sterling. 2006. African Rue (Peganum harmala) seedlings response to herbicides applied under water-deficient stress. Weed Science 54:198-204.

Abbott, L.B. and T.M. Sterling. 2003. Recovery of African rue seedlings from water stress: Implications for recruitment and invasion. Page 3 in Invasive Plants in Natural and Managed Systems: Linking Science and Management and 7th International Conference on the Ecology and Management of Alien Plant Invasion.

Decreane, L.P.R., J. Delaet, and E.F. Smets. 1996. Morphological studies of Zygophyllaceae 2. The floral development and vascular anatomy of Peganum harmala. American Journal of Botany 83:201-215.

Lee. R.D., 2004. New Mexico's invasive weeds. Las Cruces: New Mexico State University College of Agriculture and Home Economics and Cooperative Extension Service. Pp. 32-33.

Mahmoud, A., A. El-Sheikh, and S. Abdul-Basit. 1983. Gernimation of six desert species from Riyadh District, Saudi Arabia. J. Coll. Sci. King Suadi Univ. 14:5-22

Robinett, D., D. Miller, and D. Bedunah. 2008. Central Afghanistan Rangelands: A history of tribal rule, grazing, war, and rebuilding. Rangelands.30:2-12.

Thalen, D.C.P., 1979. Ecology and utilization of desert shrub rangelands in Iraq. Dr. W. Junk B.V. Publishers, The Haque, The Netherlands.

USDA. Field Guide for Managing African Rue in the Southwest. https://www.fs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb5410106.pdf

Walter, H. and E.O. Box. 1983. Caspian lowland biome. Pages 9-41 in N.E. West, ed. Ecosytems of the World 5: Temperate Deserts and Semi-Deserts. Amsterdam: Elsevier.

Whitson, T.D., editor. 2000. Weeds of the west, ninth edition. University of Wyoming, Jackson.

Data Source

Last Updated: 2024-01-23 by ARMO