Silverleaf Nightshade (Solanum elaeagnifolium)
Silverleaf nightshade (Solanum elaeagnifolium) is a native, perennial forb that is found in many types of soils and ecological sites throughout the southwestern U.S and Mexico. It is also occasionally found in the northern plains states.
- Silverleaf nightshade is a member of the potato family.
- It is an upright forb growing from 1 to 3 feet under good conditions.
- The plant is easily recognized because it is covered with tiny, densely matted hairs that give the plant a silver color.
- The stems and leaves are prickly, with wavy margins that are shaped, like a lance, to narrowly oblong.
- It reproduces from underground rootstalks and by seed.
- Soil disturbances often spread populations.
The plant flowers and produces fruit from May through October, forming blue or purple — and in rare instances white — flowers, followed by round yellow tomato-like fruit.
Silverleaf nightshade produces a toxin, solanine, in its leaves and fruit. Ripe fruits are the most toxic. The plant is not palatable but is sometimes baled with hay and fed to livestock. Severe overgrazing can also lead to problems.
Cattle and horses are the most affected by the plant, while sheep and goats are more resistant to its toxin.
Symptoms of toxicity in livestock can affect 2 major systems: the nervous system and gastrointestinal tract. Watch for signs of trembling, stumbling, labored breathing, nausea, vomiting and bloody diarrhea. Consult a veterinarian if these symptoms occur.
The plant does have one good attribute: the fruits are a source of solasodine, an ingredient used in the commercial manufacture of steroidal hormones.
Silverleaf nightshade can be controlled in pastures by a properly-timed application of herbicide.
Editor’s note: Kent Ferguson, retired rangeland management specialist from USDA Natural Resources Conservation Service (NRCS), is providing us with plant identification photo stories to help ranchers identify those forbs, forages and species growing in the pastures. Additional photos provided by USDA NRCS.
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