Weed Seed: Lepidium appelianum (Globe-pod hoary cress)

Family

Brassicaceae

Synonyms

Cardaria pubescens

Common Name

Globe-pod hoary cress

Regulation

Primary Noxious, Class 2 in the Canadian Weed Seeds Order, 2016 under the Seeds Act.

Distribution

Canadian: Occurs in AB, BC, MB, SK (Brouillet et al. 2016Footnote 1).

Worldwide: Native to central Asia and introduced in North America (Canada and the United States) and South America (Argentina) (USDA-ARS 2016Footnote 2). In the United States, it is mostly found in the western and midwestern states (Francis and Warwick 2008Footnote 3).

Duration of life cycle

Perennial

Seed/Fruit type

Seed

Seed identification features

Size

  • Seed length: 2.0 - 2.5 mm
  • Seed width: 1.3 - 1.8 mm
  • Seed thickness: 1.0 mm

Shape

  • Seed oval, compressed, the hilum area is flattened

Surface Texture

  • Seed granular

Colour

  • Seed reddish-brown

Other Features

  • Pods are globose to kidney-shaped, strongly inflated, 3.0 - 4.5 mm long and 2.5 - 4.5 mm wide, hairy
  • Seed is oval in cross-section

Habitat and Crop Association

Cultivated fields, gardens, pastures, feedlots, grasslands, orchards, roadsides, railway lines and other disturbed areas (Darbyshire 2003Footnote 4, Zouhar 2004Footnote 5). A weed of pastures and alfalfa and clover fields in Canada (Francis and Warwick 2008Footnote 3).

General Information

Contaminated alfalfa seed or horse feed was the probable introduction route for globe-pod hoary cress into North America in the early 1900s (Francis and Warwick 2008Footnote 3).

Similar species

Lens-pod hoary cress (Lepidium chalepense)

  • Lens-pod hoary cress seeds are a similar size, reddish-brown colour, rough surface and oval shape as globe-pod hoary cress.
  • Lens-pod hoary cress seeds are ovate in cross-section due to a smaller radicle than globe-pod hoary cress.

Heart-pod hoary cress (Lepidium draba subsp. draba)

  • Heart-pod hoary cress seeds are a similar size, roughened surface and oval shape as globe-pod hoary cress.
  • Heart-pod hoary cress seeds are darker brown with a surface reticulation and ovate in cross-section often with constrictions between the cotyledons and the radicle.

Photos

Globe-pod hoary cress (Lepidium appelianum) seeds and pod
Globe-pod hoary cress (Lepidium appelianum) seed
Globe-pod hoary cress (Lepidium appelianum) seed, hilum view
Globe-pod hoary cress (Lepidium appelianum) seed, close-up of the hilum
Globe-pod hoary cress (Lepidium appelianum) seed, cross-section
Globe-pod hoary cress (Lepidium appelianum) seed

Similar species

Similar species: Lens-pod hoary cress (Lepidium chalepense) seeds and pod
Similar species: Lens-pod hoary cress (Lepidium chalepense) seed
Similar species: Heart-pod hoary cress (Lepidium draba subsp. draba) pod and seeds
Similar species: Heart-pod hoary cress (Lepidium draba subsp. draba) seed
Similar species: Comparison of Lepidium spp. seed cross-sections
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