Weed Seed: Solanum carolinense (Horse nettle)




Ball nettle

Common Name

Horse nettle


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


Canadian: Occurs in ON and QC (Brouillet et al. 2016Footnote 1).

Worldwide: Native to eastern North America, from Ontario to northern Mexico, and introduced in Japan and India (Bassett and Munro 1986Footnote 2, USDA-ARS 2016Footnote 3).

Duration of Life Cycle


Seed or Fruit Type


Identification Features


  • Seed length: 1.7 - 3.5 mm
  • Seed width: 1.4 - 2.1 mm
  • Seed thickness: 0.2 mm


  • Oval shaped seed, flattened

Surface Texture

  • Faint pattern of wavy-edged cells on seed surface can be seen under magnification


  • Seed yellow to orange

Other Features

  • Hilum is a slit along the narrow edge of seed and is 0.5 mm long

Habitat and Crop Association

Cultivated fields, pastures, gardens, nurseries, riverbanks, roadsides and disturbed areas (Bassett and Munro 1986Footnote 2, Darbyshire 2003Footnote 4). Most frequently found in corn and grain fields, and to a lesser extent in pastures, alfalfa, potatoes, soybeans and tomatoes (Bassett and Munro 1986Footnote 2).

General Information

Horse nettle may produce up to 5000 seeds per plant. The seeds are apparently spread through livestock manure and the berries and horizontal roots are spread as a result of harvesting operations (Bassett and Munro 1986Footnote 2, CABI 2016Footnote 5).

Similar Species

Silverleaf nightshade (Solanum elaeagnifolium)

  • Silverleaf nightshade seeds are a similar flattened oval shape, and smooth surface as horse nettle seeds.
  • Silverleaf nightshade seeds (length: 3.0 - 4.0 mm; width: 2.3 - 3.5 mm) are generally larger than horse nettle seeds, brown coloured and the surface pattern is long, wavy lines around the outside of the seed.


Horse nettle (Solanum carolinense) seeds
Horse nettle (Solanum carolinense) seed
Horse nettle (Solanum carolinense) seed
Horse nettle (Solanum carolinense) seed

Similar species

Similar species: Silverleaf nightshade (Solanum eleagnifolium) seeds
Similar species: Silverleaf nightshade (Solanum eleagnifolium) seed
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