epiphyseal plate morphology trait epiphyseal plate proliferative zone morphology trait Any measurable or observable characteristic related to the shape, structure, color, or pattern of the germinal layer of the epiphyseal plate where cells are actively dividing as well as producing extracellular matrix. Trait.ontology VT:0003662 epiphysial plate proliferative zone morphology trait zone of proliferating cartilage morphology trait