癭 Gall
癭是指植物組織受到昆蟲或其他生物刺激而不正常增生的現象。該刺激可能是昆蟲所釋放出的化學物質，或是單純的物理刺激。其他可產生癭的生物包括真菌、細菌、蜱或是蟎等。通常透過觀察癭的特徵就能判斷其成因。
Gall is abnormal growth of plant tissue in response to an chemical or physical attack by insects, fungi, bacteria, mites etc.. The characteristic form of gall often reveals the cause of formation.
