What term is used for abnormal swelling in plants?

The term used for abnormal swelling in plants is "gall." Galls are growths that occur on various parts of a plant, caused by various factors including insect infestations, plant diseases, or chemical influences. When an organism such as an insect lays eggs on or feeds on the plant tissue, it can trigger the plant to produce these outgrowths as a defensive response or because of the hormonal changes induced by the organism. Galls can vary in size and shape, and they may develop on leaves, stems, roots, or flowers.

Chlorosis refers to a yellowing of plant tissues, typically due to nutrient deficiencies or environmental stress rather than abnormal swelling. Mosaic describes a pattern of light and dark green areas on leaves caused by viral infections, but does not involve swelling. Weeds are simply unwanted plants that hinder the growth of crops or gardens, and do not refer to a specific abnormal plant growth pattern. Therefore, "gall" accurately describes the abnormal swelling that can occur in plants due to various conditions.