A study has found that frequent mowing of Solanum elaeagnifolium, also known as silverleaf nightshade, may help create a ‘superweed.’ A professor of entomology and plant pathology has been studying silverleaf nightshade for more than a decade. New findings have shown that the more silverleaf nightshade was mowed, the more it developed ways to avoid destruction. The taproot went down further, nearly 5 feet deep, in the first generation of mowed plants. More spikes popped out on the stem as a defense against caterpillars feeding on the flowers. The flowers became more toxic to caterpillars, leading to less pressure from natural predators.