A "witches' broom" is a plant disease that affects various trees and shrubs, causing abnormal growths or clusters of twigs and leaves. These growths resemble a broom, hence the name. The condition is often caused by pathogens such as fungi, bacteria, or viruses, which disrupt the normal growth patterns of the plant. Witches' broom can be found in many species, including willows, oaks, and maples. While it may not always harm the plant significantly, it can lead to reduced vigor and increased susceptibility to other diseases. Proper management and care can help mitigate its effects on affected plants.