Peganum harmala

Keys to Identification

• The leaves are finely divided in long, narrow segments.
• Flowers are white with five petals.
• This information courtesy of the Colorado Natural Areas Program

Family

Zygophyllaceae (Caltrop)

Other Names

Syrian rue, Harmel shrub

USDA Code

PEHA

Legal Status

Colorado Noxious Weed List A

Identification

Lifecycle

Perennial

Growth form

Forb

Flower

Flowers are white, have five petals, and are borne along the stem in the leaf forks.

Seeds/Fruit

The fruit is a 2 to 4-celled leathery capsule that contains 45 – 60 seeds. Seeds are angular, dark brown with a distinctive smell. Soil seed bank viability period is currently unknown.

Leaves

Leaves are alternate, smooth, and finely divided with long narrow segments. When crushed there is a disagreeable odor

Stems

Mature plants are highly branched and grow 1.5 ft tall and 3-4 ft wide

Roots

Branching reaching to 20 feet deep

Seedling

More information is needed.

Impacts

Agricultural

African rue is toxic to livestock and can replace valuable forage subsequently reducing the productivity of pasture and rangeland.

Ecological

This plant is extremely drought tolerant, and it has expanded into desert rangelands replacing desirable native plants like saltbrush and grasses. It has a competitive advantage over native plants as it germinates earlier in the spring. Most parts of this plant contain allopathic chemicals that retard or prevent the growth of other vegetation.

Habitat and Distribution

General requirements

Adapted to relatively arid environments.

Distribution

Present throughout New Mexico and is reported in Arizona, California, Idaho, Montana, Nevada, Texas, Oregon and Washington (USDA Plant Database).

Historical

Native of northern Africa, through the Middle East to Tibet in Asia. This plant was first recorded in the United States near Deming, New Mexico in 1928.

General requirements

Is adapted to relatively arid environments.

Biology/Ecology

Mode of reproduction

Reproduces both vegetatively and by seeds.

References

USDA, NRCS. 2005. The PLANTS Database, Version 3.5 (http://plants.usda.gov). Data compiled from various sources by Mark W. Skinner. National Plant Data Center, Baton Rouge, LA 70874-4490 USA

Whitson, T.D.(ed.), L.C. Burrill, S.A. Dewey, D.W. Cudney, B.E. Nelson, R.D. Lee, R. Parker. 1996. African rue. Weeds of the West. Western Society of Weed Science, in cooperation with the Western United States Land Grant Universities Cooperative Extension Services, Newark CA. pg. 598.