Weed Seed: Peganum harmala (African-rue)

Invasive Plant - African-rue (Peganum harmala)

Family

Nitrariaceae

Common name

African-rue

Regulation

Prohibited Noxious, Class 1 in the Canadian Weed Seeds Order, 2016 under the Seeds Act. All imported and domestic seed must be free of Prohibited Noxious weed seeds.

Distribution

Canadian: Absent from Canada (Brouillet et al. 2016Footnote 1).

Worldwide: Native to desert regions of northern Africa, Asia, and southern and eastern Europe. Introduced to the United States, where it is found across the southwest and Pacific states. Populations are currently concentrated in Arizona, New Mexico and Texas (CFIA 2012Footnote 2).

Duration of life cycle

Perennial

Seed or fruit type

Seed

Identification features

Size

  • Seed length: 2.0 - 4.5 mm
  • Seed width: 1.5 - 3.0 mm

Shape

  • Trigonous seed; shaped similar to an orange wedge

Surface texture

  • Seed surface is rough, bubbled and/or covered with reticulations
  • Edges of the seed are winged

Colour

  • Seed is blackish-red to red, translucent

Other features

  • Hilum is a small hole at one end.

Habitat and crop association

Occurs mainly in dry grasslands and saline waste areas, but also common along roadsides, field edges and in degraded pastures. Prefers disturbed environments (CFIA 2012Footnote 2).

General information

African-rue has long been used as a dye plant and was imported into New Mexico in 1928 for "Turkish Red" dye (Guclu and Ozbek 2007Footnote 3). It has since spread into Texas and Arizona and along the western coast of the United States (Abbott et al. 2007Footnote 4).

Natural spread is mostly by seed, and occurs by water moving over soil or by animals that deposit the seeds in their droppings. Humans also plant this species for medicinal purposes and spread it unintentionally by moving pieces of rootstock with vehicles or machinery (CFIA 2014Footnote 5). African-rue contains alkaloids that are toxic to grazers, including horses, sheep and cattle.

Similar species

No similar species

Photos

African-rue (Peganum harmala) seeds
African-rue (Peganum harmala) seed
African-rue (Peganum harmala) seed, hilum view
African-rue (Peganum harmala) capsule
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