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Class A Noxious Weed

Silverleaf Nightshade
Solanum elaeagnifolium
 

Silverleaf nightshade flower

Other common names: Purple nightshade, White horsenettle, Tomato weed
 Plant family: Solanaceae
Year listed: 1999
Native to: Europe

Why is it a noxious weed?

Silverleaf nightshade lowers crop yield through competition. The species is also toxic to livestock. Silverleaf nightshade contains toxic alkaloids that combine with sugars to produce glycoalkaloids that irritate the gastrointestinal tract.

How would I identify it?
General Description: Silverleaf nightshade is branched, deep rooted perennial herb that grows 1 - 4 feet in height.

Leaves:

  • lanceolate 
  • 1 - 4 inches long by 1 inch wide
  • wavy margins
  • short silvery-white hairs give the plant a dusky or silvery-gray color

Flowers:

  • blue, violet or rarely white flowers
  • 5 fused petals, ¾ inch across
  • bright yellow stamens

Stems:

  • stems have slender yellow spines

Line drawings are taken from 1,000 Weeds of North America, copyright of XID Service, Inc and used with permission. Permission granted by the author.

How does it reproduce?
Silverleaf nightshade reproduces by seed, rhizomes and root fragments.

Where does it grow?
Silverleaf nightshade is adapted to semi-arid regions. It will grow in pastures, cultivated fields and roadsides.

What is the distribution in Washington State?
 

 

  • Distribution map not available at this time.

How do I control it?

General control methods:

Cultural: Cultivation will not readily kill silverleaf nightshade, frequent thorough cultivation is required. Shade crops may be effective. However, silverleaf nightshade must be inhibited until the shade crop has a chance to thrive.

Herbicide: This plant is difficult to control with herbicide because of it's root system. Please refer to the PNW Weed Management Handbook, or contact your county noxious weed coordinator.

Mechanical: Plants can regrow after being clipped or mowed.

Biological: Several biocontrol agents have been investigated. The most promising organism is a foliar
nematode, Orrina phyllobia, which causes leaf and stem galling.

For more information
For more information, download our Written Findings.

 

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Silverleaf nightshade infestation
Silverleaf Nightshade infestation photo. Silverleaf Nightshade full plant, notice the bushy habit.

 Last updated July 09, 2008