Weed Seed: Solanum elaeagnifolium (Silverleaf nightshade)

Invasive Plant - Silverleaf nightshade (Solanum elaeagnifolium)

Family

Solanaceae

Common name

Silverleaf nightshade

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.

Listed on the List of Pests Regulated by Canada established under the Plant Protection Act.

Distribution

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

Worldwide: Native to northeastern Mexico and the southwestern United States. Introduced elsewhere in North and South America and currently widespread in the U.S in all but the Great Lakes and New England regions (CFIA 2012Footnote 2). Also introduced to Australia, India, South Africa, and around the Mediterranean basin (CFIA 2014Footnote 3).

Duration of life cycle

Perennial

Seed or fruit type

Seed

Identification features

Size

  • Seed length: 3.0 - 4.0 mm
  • Seed width: 2.3 - 3.5 mm
  • Seed thickness: 1.0 mm

Shape

  • Round to oval-shaped seed, strongly compressed, notched at the hilum

Surface texture

  • Smooth with faint wavy lines, most evident along the edges of the seed

Colour

  • Seed medium brown

Other features

  • Hilum is a wide oval opening on narrow edge

Habitat and crop association

Cultivated fields, rangelands, grasslands, forests, coastal areas, marshes, riverbanks, roadsides and other disturbed areas, particularly in areas of low annual rainfall (CABI 2016Footnote 4). Affects a variety of crops, the main ones being alfalfa, citrus, corn, cotton, sorghum and wheat (CABI 2016Footnote 4).

General information

Silverleaf nightshade reproduces by both seed and root fragments. Plants produce up to 250 million seeds per hectare and the seeds can remain viable for up to 10 years (Boyd and Murray 1982Footnote 5). All parts of the plant, especially the fruit, are poisonous to livestock (CABI 2016Footnote 4).

Similar species

Horse-nettle (Solanum carolinense)

  • Similar shape and smooth surface as silverleaf nightshade.
  • Horse nettle seeds are generally shorter and narrower with a size of 2.5 - 3.5 mm length and 1.5 - 2.0 mm width; an orange colour, and a faint reticulate pattern over the entire surface compared to silverleaf nightshade.

Photos

Silverleaf nightshade (Solanum elaeagnifolium) seeds
Silverleaf nightshade (Solanum elaeagnifolium) seed
Silverleaf nightshade (Solanum elaeagnifolium) dried fruit (berry) with visible seeds

Similar species

Similar species: Horse-nettle (Solanum carolinense) seeds
Similar species: Horse-nettle (Solanum carolinense) seed