African Rue (Peganum harmala)

Description:

African rue is a multi-branched and bushy perennial of the Caltrop family. It is a succulent plant, with bright green alternating leaves that are smooth and finely divided with long, narrow segments. Plants grow 1.5 feet tall and 3-4 feet in diameter. Flowers are white with five individual petals and are present in spring to early fall. Fruit is located in a leathery capsule 2-4 celled that contains 45-60 seeds. Seeds are angular, dark brown and have a distinctive smell. When crushed, the stems also have a disagreeable odor. The base of this plant is woody and roots can branch and reach 20 feet in depth. African rue prefers disturbed environments such as roadsides, fields and rangelands in desert and semi-desert areas. It is often found in soils with high salinity and most parts of the plant contain allelopathic chemicals that reduce growth of other vegetation.

Life cycle:

Perennial

Height of mature plants

18 inches

Flower color:

White

Bloom time:

It can bloom from April through November.

Look-a-likes:

None

Habitat:

African rue primarily grows in deserts.

Impacts:

African rue contains at least four poisonous alkaloids. It is toxic to people and livestock. The seeds and fruit of the plant are the most toxic part with a lethal dose being 0.15 percent of an animal’s body weight. Young leaves are less toxic then seeds with a lethal dose of about 1.0 percent of the animal’s weight, while mature leaves are less toxic. Dry
leaves are apparently nontoxic. This noxious weed is extremely drought tolerant and displays robust vegetative growth expanding into desert rangelands replacing native plants like salt brush and grasses. It has a competitive advantage over native plants as it germinates earlier in the spring.

Noxious Weed Listing:

• WeedWise: Priority
• State of Oregon: Class A,T
• State of Washington: not listed
• Four County CWMA: not listed

Origin:

Africa, South Asia

Present in Clackamas County:

No

Links:

Oregon Noxious Weed Pprofile