SRI Project Index

Santa Rosa Island Noxious Weed Survey and Eradication

 

A project of the Santa Cruz Island Native Plant Restoration Project

and the Santa Barbara County Weed Management Area

 

White Horsenettle (Solanum elaeagnifolium)

 

White horsenettle, Solanum elaeagnifolium, also known as silverleaf nightshade, is designated by the California Department of Food and Agriculture as a "B" rated noxious weed. "B" rated noxious weeds are plants of know economic importance subject to enforcement action and are a high priority for control by the CDFA and the SBCWMA. Populations of this weed are of limited distribution in California. In Santa Barbara County it has been slowly spreading on Santa Cruz Island from the Christy Barn area to the Christy airfield area and in Cebada Canyon, but is still very localized. It is found on Santa Rosa Island as well. Additional historical collections have been made at the Bishop Ranch near Goleta, along a Solvang roadside, along Meigs Road in Santa Barbara, and at the mouth of Rattlesnake Canyon.

Solanum elaeagnifolium (family Solanaceae) is a perennial that spreads by roots or seeds. Stems are sparsely covered with short yellow prickles. The berries and foliage are poisonous to humans and livestock. Upper leaf surfaces except margins are sparsely covered with star-shaped hairs. Leaf margins are whitish, covered with white star-shaped hairs. Lower leaf surfaces are cottony white, densely covered with a mat of white star-shaped hairs that appear iridescent with magnification and bright light. Large infestations could potentially compete with native plants for nutrients and moisture. It is believed to have allelopathic properties

 

Solanum elaeagnifolium blooms from May to September. Flowers are purple to blue, with a classic nightshade look - star shaped with 5 lobes.

 

For more information and photos:

Encycloweedia: http://www.cdfa.ca.gov/phpps/ipc/weedinfo/solanum-carolinense.htm

NRCS Plants Profile: http://plants.usda.gov/java/profile?symbol=SOEL

Uvalde Center: http://uvalde.tamu.edu/herbarium/soel.htm

CalPhotos: http://calphotos.berkeley.edu/cgi/img_query?stat=BROWSE_IMG&query_src=photos_browseimgs_plant_sci&where-genre=Plant&where-taxon=Solanum+elaeagnifolium

 

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