part of xylem development xylem vessel member cell differentiation GO:0048759 biological_process The process in which a relatively unspecialized cell acquires specialized features of a vessel member cell. A vessel member cell is one of the components of a vessel in the xylem. It is a dead cell with the wall between adjacent members being variously perforated and the walls that persist variously thickened. vessel member cell differentiation vessel element cell differentiation tracheary element differentiation