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Globe-Podded Hoary Cress

Globe-podded hoary cress
Photo Credit: Mary Ellen Harte, United States, retrieved from Bugwood.org (Image Number: 5089054), used under CC BY-NC 3.0 US, modified from the original

Common Name: Globe-Podded Hoary Cress

Scientific Name: Lepidium appelianum

Habitat: roadsides, disturbed areas, farmland, grassland, grassland dry, grassland wet

Provincial Designation: Noxious

Noxious weeds are plant species that are designated as "noxious weeds" in the Alberta weed regulation. Noxious weeds must be controlled, meaning their growth or spread needs to be prevented.

Origin

Globe-podded hoary cress, also called pepper-grass, is native to Europe and Asia. Together with the closely related lens-podded hoary cress, it was introduced to North America in the early 1900s. It was likely introduced as a contaminant of alfalfa seed or horse feed. The seeds have been used to make pepper, hence the common name of pepper-grass.

Legislated Because

Globe-podded hoary cress can be an aggressive invader that forms dense monocultures in open grasslands and riparian areas. It also serves as a host for insect pests of crops.

Description

This weed has 5-8 mm wide white flowers with four petals. Numerous flowers are borne at the end of the stem in flat topped clusters.

The leaves are 1-5 cm long, covered with soft hairs, grey-green or blue-green in colour, and usually clasp the stem. The leaf shape is oblong or lance-shaped and the leaf edges are toothed. A key characteristic of this weed is that is has inflated spherical fruits that are covered in short simple hairs.

Stems are erect, sometimes have hairs, and grow 15-35 cm high.