Final answer:
The name of an era when vegetation hasn't been influenced by humans is known as the pristine or undisturbed era.
Step-by-step explanation:
The name of an era when vegetation hasn't been influenced by humans is known as the pristine or undisturbed era. During this era, the vegetation remains unaffected by human activities such as deforestation, agriculture, or urbanization. Pristine habitats are those that have not undergone significant human disturbance, preserving their natural state.
However, it is important to note that archaeological and paleoecological studies have revealed that many so-called pristine habitats have actually experienced some form of human impact in the past.