White Horsenettle

Here's a closeup of the flower.

And here's a good view of the plant, showing the berries, too. Solanum elaeagnifolium Solanacaea (Nightshade family) Common names: White Horsenettle, Silver Horsenettle, Silverleaf Nightshade, Bullnettle Location: Zion National Park, Pa'ruse Trail near Human History Museum. May 14, 2008. Open fields on dry plain adjacent to the Virgin River. Elevation: approx 4000 feet NAD83 UTM: 12S 324500 mE 4120100 mN Dominance: Not common in the area Comments: Described as an aggressive, poisonous weed, spreading steadily from deep rootstocks. Source: Spellenberg, Richard. (1979, 1994) National Audubon Society Field Guide to North American Wildflowers, Western Region. Alfred A. Knopf, New York. ISBN 0-394-50431-3. photo plate 584, description page 789.