part of formation of structure involved in a symbiotic process appressorium formation appressorium maturation maturation of symbiont appressorium on or near host appressorium maturation on or near host The process in which specialized features of the symbiont appressorium are acquired post initiation, to aid in infection of the host. The host is defined as the larger of the organisms involved in a symbiotic interaction. maturation of appressorium on or near host GO:0075035 biological_process