Aster yellows is a classic example of a virus disease in the yellows group. Symptoms include a general yellowish color. Often a plant is affected unilaterally, one branch at a time, while the rest of the plant appears healthy. Dormant buds are stimulated and yellow, and thin branches with long internodes appear in profusion to produce the characteristic witch’s broom. Roots may also proliferate. Flower parts are often leaf-like in shape and color, and flowering may cease altogether. Plants may be stunted.