Male with an external subgular vocal sac and black nuptial excrescences on the thumb. Pliny details 25 remedies using preparation from the bark, leaves and excrescences of plane. Branchlets are dark reddish brown, shining, covered with small excrescences. It has different cheilocystidia, with very slender excrescences. These latter excrescences are embedded in gelatinous matter. Males in reproduction lack cornified nuptial excrescences . Hilar thorny excrescences are more dense and complex than those in CA3. The artist and critic Arnold Shore criticised the two lift towers as&colon; "monstrous excrescences". Many old galls bear numerous dark brown excrescences, due to the fungus "Phoma gallorum". The excrescences are unevenly spaced, simple to somewhat branched, cylindrical, and straight or curved. Males have enlarged non-projecting prepollex (the "spikethumb") but not nuptial excrescences.